A method and system for allocating power grid emergency plans

Abstract

The present application relates to a method and system for allocating emergency plans for power grids, which belongs to the field of data analysis and processing; wherein, a method for allocating emergency plans for power grids includes obtaining unit fault information of a power grid coverage area; the power grid coverage area includes multiple power grid areas; the power grid area includes multiple cell areas; the unit fault information includes fault level information and fault possibility information of the cell area; the regional fault score of each of the power grid areas is obtained according to the unit fault information and a preset fault information formula; an emergency plan database is retrieved; based on a preset emergency plan allocation rule, the emergency plans in the emergency plan database are screened according to the regional fault score to obtain the emergency plan allocation information of each of the power grid areas. The present application has the effect of optimizing the allocation of emergency plans.

Description

Technical Field

[0001] The present application relates to the field of data analysis and processing, and in particular to a method and system for allocating emergency plans for power grids. Background Art

[0002] In order to ensure the safe and stable operation of the power grid, improve the ability to deal with sudden power outages in the power grid and standardize emergency response to large-scale power outages, it is necessary to set up emergency plans for regional power grids to ensure that power grid emergencies can be handled correctly, effectively and quickly, and reduce the impact and losses caused by power grid emergencies; since there are many situations of power grid accidents, the pre-set emergency plans are also constructed for different situations of power grid accidents. Therefore, when a power grid accident occurs, it is very important to better control and distribute the established emergency plans. Summary of the invention

[0003] In order to solve the above technical problems, the present application provides a power grid emergency plan allocation method and system.

[0004] The first purpose of this application is to provide a method for allocating power grid emergency plans.

[0005] The above-mentioned application objective 1 of the present application is achieved through the following technical solutions:

[0006] A method for allocating power grid emergency plans, comprising:

[0007] Acquire unit fault information of a power grid coverage area; the power grid coverage area includes multiple power grid areas; the power grid area includes multiple cell areas; the unit fault information includes fault level information and fault possibility information of the cell area;

[0008] Obtaining a regional fault score for each of the power grid areas according to the unit fault information and a preset fault information formula;

[0009] Retrieving an emergency plan database, wherein the emergency plan database includes multiple emergency plans and emergency plan capability information; the emergency plan capability information includes emergency plan level information and emergency plan capability score information;

[0010] Based on the preset emergency plan allocation rule, the emergency plans in the emergency plan database are screened according to the regional fault scores to obtain emergency plan allocation information for each of the power grid areas.

[0011] In a preferred example, the present application can be further configured to include:

[0012] Obtaining an emergency plan processing capability score for each of the power grid areas according to the emergency plan allocation information;

[0013] Obtaining the emergency control capability ratio of each power grid area according to the regional fault score and the emergency plan processing capability score;

[0014] The control effect score of the grid coverage area is calculated according to the emergency control capability ratio of each grid area in the grid coverage area;

[0015] The control evaluation information of the grid coverage area is obtained according to the control effect score and preset control evaluation rules.

[0016] In a preferred example, the present application may be further configured as follows:

[0017]

[0018] Among them, Z represents the cell fault degree score, D represents the fault level information of each cell area, K represents the fault possibility information of each cell area; i takes the value of 1-n, indicating the 1st-nth faults existing in the cell area; Di*Ki represents the fault degree value of each cell area; S represents the fixed score corresponding to each fault degree; f(Di,Ki) is a preset piecewise function.

[0019] In a preferred example, the present application may be further configured as follows: based on the preset emergency plan allocation rule, the emergency plans in the emergency plan database are screened according to the regional fault score to obtain the emergency plan allocation information for each of the power grid areas, including:

[0020] Based on a preset emergency plan allocation rule, determining first screening information according to the regional fault score;

[0021] Based on a preset emergency plan allocation rule, determining second screening information according to the fault level information of the cell area;

[0022] Based on the preset emergency plan allocation rule, determining the third screening information according to the preset emergency plan quantity threshold;

[0023] The emergency plan allocation information of each of the power grid areas is determined according to the first filtering information, the second filtering information and the third filtering information.

[0024] In a preferred example, the present application can be further configured as follows: based on the preset emergency plan allocation rules, determining the first filtering information according to the regional fault score includes obtaining an emergency plan capability threshold according to the regional fault score and a preset coverage value; and determining the first filtering information according to the preset emergency plan allocation rules and the emergency plan capability threshold.

[0025] In a preferred example, the present application can be further configured to include:

[0026] Obtaining a preset cost for each of the emergency plans based on an emergency plan database;

[0027] Determine a plurality of emergency plan groups according to the emergency plan allocation information; each of the emergency plan groups includes a plurality of emergency plans;

[0028] Obtaining a total cost value of each of the emergency plan groups according to the preset cost;

[0029] Determining the total capacity value of each of the emergency response plan groups;

[0030] The allocation efficiency evaluation information of the emergency plan allocation information is determined according to the total capability value and the total cost value.

[0031] The second purpose of this application is to provide a power grid emergency plan distribution system.

[0032] The second application objective of the present application is achieved through the following technical solutions:

[0033] A power grid emergency plan distribution system, comprising:

[0034] An acquisition module, used to acquire unit fault information of a power grid coverage area; the power grid coverage area includes multiple power grid areas; the power grid area includes multiple cell areas; the unit fault information includes fault level information and fault possibility information of the cell area;

[0035] A calculation module, used for obtaining a regional fault score of each of the power grid areas according to the unit fault information and a preset fault information formula;

[0036] A retrieval module is used to retrieve an emergency plan database, wherein the emergency plan database contains multiple emergency plans and emergency plan capability information; the emergency plan capability information contains emergency plan level information and emergency plan capability score information;

[0037] The allocation module is used to screen the emergency plans in the emergency plan database according to the regional fault scores based on the preset emergency plan allocation rules to obtain emergency plan allocation information for each of the power grid areas.

[0038] In a preferred example, the present application may be further configured as follows: the calculation module is further configured as follows: the preset fault information formula includes:

[0039]

[0040] Among them, Z represents the cell fault degree score, D represents the fault level information of each cell area, K represents the fault possibility information of each cell area; i takes the value of 1-n, indicating the 1st-nth faults existing in the cell area; Di*Ki represents the fault degree value of each cell area; S represents the fixed score corresponding to each fault degree; f(Di,Ki) is a preset piecewise function.

[0041] The third purpose of this application is to provide a terminal.

[0042] The third application objective of this application is achieved through the following technical solutions:

[0043] A terminal comprises a memory and a processor, wherein the memory stores computer program instructions of the above-mentioned power grid emergency plan allocation method which can be loaded and executed by the processor.

[0044] The fourth object of this application is to provide a computer medium capable of storing corresponding programs.

[0045] The fourth application objective of this application is achieved through the following technical solutions:

[0046] A computer-readable storage medium stores a computer program that can be loaded by a processor and execute any of the above-mentioned power grid emergency plan allocation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of a method for allocating power grid emergency plans in an embodiment of the present application.

[0048] Figure 2 It is a structural diagram of a power grid emergency plan distribution system in an embodiment of the present application.

[0049] Explanation of the accompanying drawings: 1. Acquisition module; 2. Calculation module; 3. Retrieval module; 4. Allocation module. DETAILED DESCRIPTION

[0050] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the Patent Law.

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] The embodiments of the present application are further described in detail below in conjunction with the drawings in the specification.

[0053] The present application provides a method for allocating emergency plans for a power grid, and the main process of the method is described as follows.

[0054] like Figure 1 As shown:

[0055] Step S101: Acquire unit fault information of a power grid coverage area; the power grid coverage area includes multiple power grid areas; the power grid area includes multiple cell areas; the unit fault information includes fault level information and fault possibility information of the cell area.

[0056] For the grid coverage area, it represents the area covered by the grid, which contains multiple grid areas, and each grid area contains multiple cell areas; for each cell area, it may not be connected to the grid, so its fault level information and fault possibility information are both zero; it may also be connected to the grid, and by obtaining the unit fault information, the fault level of the cell area and the corresponding probability of occurrence of different levels of faults can be obtained.

[0057] Step S102: obtaining a regional fault score for each of the power grid areas according to the unit fault information and a preset fault information formula.

[0058] Among them, the preset fault information formula includes:

[0059]

[0060] Where Z represents the cell fault degree score, D represents the fault level information of each cell area, and K represents the fault possibility information of each cell area; i takes values ​​of 1-n, indicating the 1st-nth fault in the cell area; D i *K i represents the fault degree value of each cell area; S represents the fixed score corresponding to each fault degree; f(D i ,K i ) is the preset piecewise function.

[0061] After the fault degree score of each cell is calculated by the preset fault information formula, the cells of each power grid area are clustered based on the fault degree score based on the cluster analysis algorithm to obtain the regional fault score of each power grid area.

[0062] f(D i ,K i ) is a preset piecewise function, that is, in f, when D i and K i When it is in the first data range, the function result is the first value, and when the accumulated power-off duration is in the second data range, the function result is the second value; it should be noted that the value of f here also depends on D i and K i There are two variables, so f can only take the corresponding value when both of them meet the corresponding range judgment conditions.

[0063] In the embodiment of the present application, the fault level includes 1-5 levels, and the fault probability includes 0-99%; if D i 1 (1 means the fault level is 1, D i =1 means that the cell has a level 1 fault), and K i When f(D i ,K i )=0;D i is 2-4, and K i When it is 0-20% (including 0 and 20%), f(D i ,K i )=0;D i is 2-4, and K i When it is 20%-99% (excluding 20% ​​and including 99%), f(D i ,K i )=1;D i is 5, and K i When it is 0-10% (including 0 and 10%), f(D i ,K i )=0;D i is 5, and K i When it is 10%-99% (excluding 10% and including 99%), f(D i ,K i )=1.

[0064] Step S103: Retrieve an emergency plan database, wherein the emergency plan database includes multiple emergency plans and emergency plan capability information; the emergency plan capability information includes emergency plan level information and emergency plan capability score information.

[0065] Step S104: Based on the preset emergency plan allocation rule, the emergency plans in the emergency plan database are screened according to the regional fault score to obtain emergency plan allocation information for each of the power grid areas.

[0066] In an embodiment of the present application, based on a preset emergency plan allocation rule, the emergency plans in the emergency plan database are screened according to the regional fault score to obtain the emergency plan allocation information for each of the power grid areas, specifically including: based on the preset emergency plan allocation rule, determining first filtering information according to the regional fault score; based on the preset emergency plan allocation rule, determining second filtering information according to the fault level information of the cell area; based on the preset emergency plan allocation rule, determining third filtering information according to a preset emergency plan quantity threshold; and determining the emergency plan allocation information for each of the power grid areas according to the first filtering information, the second filtering information and the third filtering information.

[0067] Among them, based on the preset emergency plan allocation rules, determining the first filtering information according to the regional fault score includes obtaining the emergency plan capability threshold according to the regional fault score and the preset coverage value; and determining the first filtering information according to the preset emergency plan allocation rules and the emergency plan capability threshold.

[0068] In an embodiment of the present application, the preset emergency plan allocation rule includes three formulas, which correspond to the first filtering information, the second filtering information and the third filtering information respectively.

[0069] Among them, the first formula corresponds to the first screening information, and the first formula is as follows:

[0070]

[0071] Wherein, P represents the capability score corresponding to the emergency plan level, E represents the quantity value corresponding to the emergency plan level; x takes a value of 1-5, x represents the emergency plan level, in the embodiment of the present application, the emergency plan level includes 1-5 levels, which correspond to the fault level one by one, and the fault requires an emergency plan of the same level or higher level to solve; Z represents the cell fault degree score, h takes a value of 1-u, which represents the number of cells in each power grid area, Represents the regional fault score of each power grid area; R represents the preset coverage value; through the first formula, it is ensured that the total capacity value of the emergency plan allocation combination obtained by screening needs to cover at least a certain degree of regional fault score; it can be understood that the value of R here can be 80%, 90%, 100%, or even more than 100%, that is, for the screened emergency plan combination, its total capacity value needs to cover at least 80% of the faults in the power grid area, and such an emergency plan combination can be regarded as able to solve the faults.

[0072] The second formula corresponds to the second screening information, and the second formula is as follows:

[0073] If x=D, E x ≠0;

[0074] It can be understood that D represents the fault level and x represents the emergency plan capability level. When the two are the same, the number of emergency plans of the same level cannot be zero; that is, as mentioned above, a fault requires an emergency plan of the same level or higher level to be resolved. Therefore, for a fault of the same level D, an emergency plan of the same level x as the fault level D is required to be resolved. Then the emergency plan of the same level x as the fault level D cannot be zero, and it is necessary to ensure that there is at least one emergency plan of the same level x as the fault level D.

[0075] The third formula corresponds to the third screening information, and the third formula is as follows:

[0076] E 1 +E 2 +E 3 +E 4 +E 5 ≤E max ;

[0077] Where E max It represents the preset emergency plan quantity threshold, that is, for the final emergency plan allocation combination, the sum of the emergency plans contained therein cannot exceed the established quantity threshold.

[0078] The final emergency plan allocation information is obtained in the above manner. However, during the allocation process, there may be multiple allocation situations. Therefore, it is necessary to further analyze the emergency plan allocation situation and screen out the optimal solution.

[0079] In an embodiment of the present application, it also includes obtaining an emergency plan processing capability score for each of the power grid areas based on the emergency plan allocation information; obtaining an emergency control capability ratio for each power grid area based on the regional fault score and the emergency plan processing capability score; obtaining a control effect score for the power grid coverage area based on the emergency control capability ratios of each power grid area within the power grid coverage area; and obtaining control evaluation information for the power grid coverage area based on the control effect score and preset control evaluation rules.

[0080] It can be understood that the emergency control capacity ratio can be obtained by dividing the regional fault score by the emergency plan handling capacity score, which ratio represents the fault score that can be handled per unit capacity score; the emergency control capacity ratios of each power grid area in the power grid coverage area are calculated, and then the sum of the emergency control capacity ratios is calculated and divided by the number of power grid areas to obtain the average value, that is, the control effect score; through the preset control evaluation rules, the control effect score is compared with the preset control effect threshold. The closer the two are, the better the control effect of the power grid coverage area. Conversely, the control effect of the power grid coverage area is poor.

[0081] It is understandable that, as mentioned in the above process, the preset coverage value can be set in advance, and the preset coverage value is set to 100%, which means that the adopted emergency plan allocation combination can completely cover the faults in the power grid area; exceeding 100%, it can include consideration of special circumstances; below 100%, it is within an acceptable operating range; although the adopted emergency plan allocation combination makes the preset coverage value meet not less than 100% to achieve the best fault coverage effect, different emergency plans have different costs, so further analysis is needed.

[0082] In an embodiment of the present application, it also includes obtaining a preset cost of each of the emergency plans based on an emergency plan database; determining multiple emergency plan groups based on the emergency plan allocation information; each of the emergency plan combinations contains multiple emergency plans; obtaining a total cost value of each of the emergency plan groups based on the preset cost; determining a total capacity value of each of the emergency plan groups; and determining allocation efficiency evaluation information of the emergency plan allocation information based on the total capacity value and the total cost value.

[0083] Through the above method, the cost of each emergency plan group is considered, the cost and capacity value are calculated comprehensively, and the capacity value brought by each unit cost can be obtained by dividing the total capacity value by the total cost value. The allocation efficiency of each emergency plan group can be determined through this parameter. The higher the capacity value brought by each unit cost, the higher the allocation efficiency of the emergency plan group, and the higher its evaluation will naturally be; conversely, the allocation efficiency is low and the evaluation will naturally be low.

[0084] The present application also provides a power grid emergency plan distribution system, such as Figure 2As shown, a power grid emergency plan allocation system includes, an acquisition module, used to acquire unit fault information of a power grid coverage area; the power grid coverage area includes multiple power grid areas; the power grid area includes multiple cell areas; the unit fault information includes fault level information and fault possibility information of the cell area; a calculation module, used to obtain regional fault scores of each of the power grid areas according to the unit fault information and a preset fault information formula; a retrieval module, used to retrieve an emergency plan database, the emergency plan database includes multiple emergency plans and emergency plan capability information; the emergency plan capability information includes emergency plan level information and emergency plan capability score information; an allocation module, used to screen the emergency plans in the emergency plan database according to the regional fault score based on a preset emergency plan allocation rule to obtain emergency plan allocation information for each of the power grid areas.

[0085] The calculation module is further configured such that the preset fault information formula includes:

[0086]

[0087] Among them, Z represents the cell fault degree score, D represents the fault level information of each cell area, K represents the fault possibility information of each cell area; i takes the value of 1-n, indicating the 1st-nth faults existing in the cell area; Di*Ki represents the fault degree value of each cell area; S represents the fixed score corresponding to each fault degree; f(Di,Ki) is a preset piecewise function.

[0088] The allocation module is further configured to determine the first filtering information according to the regional fault score based on the preset emergency plan allocation rule; determine the second filtering information according to the fault level information of the cell area based on the preset emergency plan allocation rule; determine the third filtering information according to the preset emergency plan quantity threshold based on the preset emergency plan allocation rule; determine the emergency plan allocation information of each of the power grid areas according to the first filtering information, the second filtering information and the third filtering information; obtain the emergency plan capacity threshold according to the regional fault score and the preset coverage value; determine the first filtering information according to the preset emergency plan allocation rule and the emergency plan capacity threshold.

[0089] The power grid emergency plan allocation system is further configured to obtain an emergency plan processing capability score for each of the power grid areas according to the emergency plan allocation information; obtain an emergency control capability ratio for each power grid area according to the regional fault score and the emergency plan processing capability score; obtain a control effect score for the power grid coverage area according to the emergency control capability ratios of each power grid area within the power grid coverage area; obtain control evaluation information for the power grid coverage area according to the control effect score and preset control evaluation rules; obtain a preset cost for each of the emergency plans based on an emergency plan database; determine multiple emergency plan groups according to the emergency plan allocation information; each of the emergency plan combinations includes multiple emergency plans; obtain a total cost value for each of the emergency plan groups according to the preset cost; determine a total capability value for each of the emergency plan groups; and determine allocation efficiency evaluation information for the emergency plan allocation information according to the total capability value and the total cost value.

[0090] In order to better execute the program of the above method, the present application also provides a terminal, which includes a memory and a processor.

[0091] The memory may be used to store instructions, programs, codes, code sets or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function, and instructions for implementing the above-mentioned power grid emergency plan allocation method, etc.; the data storage area may store data involved in the above-mentioned power grid emergency plan allocation method, etc.

[0092] The processor may include one or more processing cores. The processor calls the data stored in the memory by running or executing the instructions, programs, code sets or instruction sets stored in the memory, performs various functions of the present application and processes data. The processor may be at least one of a special purpose integrated circuit, a digital signal processor, a digital signal processing device, a programmable logic device, a field programmable gate array, a central processing unit, a controller, a microcontroller and a microprocessor. It is understandable that for different devices, the electronic device used to implement the above-mentioned processor function can also be other, and the embodiments of the present application are not specifically limited.

[0093] The present application also provides a computer-readable storage medium, for example, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes. The computer-readable storage medium stores a computer program that can be loaded by a processor and execute the above-mentioned power grid emergency plan allocation method.

[0094] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the aforementioned disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A method for allocating power grid emergency plans, characterized in that: include: Obtain unit fault information in the grid coverage area; The grid coverage area includes a plurality of grid areas; the grid area includes a plurality of cell areas; The unit fault information includes fault level information and fault possibility information of the cell area; Obtaining a regional fault score for each of the power grid areas according to the unit fault information and a preset fault information formula; Retrieving an emergency plan database, wherein the emergency plan database includes multiple emergency plans and emergency plan capability information; the emergency plan capability information includes emergency plan level information and emergency plan capability score information; Based on the preset emergency plan allocation rule, the emergency plans in the emergency plan database are screened according to the regional fault score to obtain emergency plan allocation information for each of the power grid areas; The preset fault information formula includes: Where Z represents the cell fault degree score, D represents the fault level information of each cell area, and K represents the fault possibility information of each cell area; i takes values ​​of 1-n, indicating the 1st-nth fault in the cell area; D i *K i represents the fault degree value of each cell area; S represents the fixed score corresponding to each fault degree; f(D i ,K i ) is the preset piecewise function.

2. The method for allocating power grid emergency plans according to claim 1, characterized in that: Also includes: Obtaining an emergency plan processing capability score for each of the power grid areas according to the emergency plan allocation information; Obtaining the emergency control capability ratio of each power grid area according to the regional fault score and the emergency plan processing capability score; The control effect score of the grid coverage area is calculated according to the emergency control capability ratio of each grid area in the grid coverage area; The control evaluation information of the grid coverage area is obtained according to the control effect score and preset control evaluation rules.

3. The method for allocating power grid emergency plans according to claim 1, characterized in that: The method of screening the emergency plans in the emergency plan database according to the regional fault score based on the preset emergency plan allocation rule to obtain the emergency plan allocation information for each of the power grid areas includes: Based on a preset emergency plan allocation rule, determining first screening information according to the regional fault score; Based on a preset emergency plan allocation rule, determining second screening information according to the fault level information of the cell area; Based on the preset emergency plan allocation rule, determining the third screening information according to the preset emergency plan quantity threshold; The emergency plan allocation information of each of the power grid areas is determined according to the first filtering information, the second filtering information and the third filtering information.

4. The method for allocating power grid emergency plans according to claim 3, characterized in that: The determining of the first screening information according to the regional fault score based on the preset emergency plan allocation rule includes obtaining an emergency plan capability threshold according to the regional fault score and a preset coverage value; The first screening information is determined according to the preset emergency plan allocation rule and the emergency plan capability threshold.

5. The method for allocating power grid emergency plans according to claim 1, characterized in that: Also includes: Obtaining a preset cost for each of the emergency plans based on an emergency plan database; Determine a plurality of emergency plan groups according to the emergency plan allocation information; each of the emergency plan groups includes a plurality of emergency plans; Obtaining a total cost value of each of the emergency plan groups according to the preset cost; Determining the total capacity value of each of the emergency response plan groups; The allocation efficiency evaluation information of the emergency plan allocation information is determined according to the total capability value and the total cost value.

6. A power grid emergency plan distribution system, characterized in that: include: An acquisition module, used to acquire unit fault information in a power grid coverage area; The grid coverage area includes a plurality of grid areas; the grid area includes a plurality of cell areas; The unit fault information includes fault level information and fault possibility information of the cell area; A calculation module, used for obtaining a regional fault score of each of the power grid areas according to the unit fault information and a preset fault information formula; A retrieval module is used to retrieve an emergency plan database, wherein the emergency plan database contains multiple emergency plans and emergency plan capability information; the emergency plan capability information contains emergency plan level information and emergency plan capability score information; An allocation module, configured to screen the emergency plans in the emergency plan database according to the regional fault score based on a preset emergency plan allocation rule to obtain emergency plan allocation information for each of the power grid areas; The calculation module is configured such that the preset fault information formula includes: Among them, Z represents the cell fault degree score, D represents the fault level information of each cell area, K represents the fault possibility information of each cell area; i takes the value of 1-n, indicating the 1st-nth faults existing in the cell area; Di*Ki represents the fault degree value of each cell area; S represents the fixed score corresponding to each fault degree; f(Di,Ki) is a preset piecewise function.

7. A terminal, characterized in that: The invention comprises a memory and a processor, wherein the memory stores computer program instructions which can be loaded by the processor and execute any one of the methods in claims 1 to 5.

8. A computer-readable storage medium, characterized in that: A computer program is stored which can be loaded by a processor and executes the method according to any one of claims 1 to 5.

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