D1. Zero-One (Easy Version)time limit per test3 secondsmemory limit per test512 megabytesinputstandard inputoutputstandard outputThis is the easy version of the problem. In this version, n \le 3000, x \ge y holds. You can make hacks only if both versions of the problem are solved.You are given two binary strings a and b, both of length n. You can do the following operation any number of times (possibly zero).   Select two indices l and r (l < r).  Change a_l to (1 - a_l), and a_r to (1 - a_r).  If l + 1 = r, the cost of the operation is x. Otherwise, the cost is y. You have to find the minimum cost needed to make a equal to b or say there is no way to do so.InputThe first line contains one integer t (1 \le t \le 600) — the number of test cases.Each test case consists of three lines. The first line of each test case contains three integers n, x, and y (5 \le n \le 3000, 1 \le y \le x \le 10^9) — the length of the strings, and the costs per operation.The second line of each test case contains the string a of length n. The string only consists of digits 0 and 1.The third line of each test case contains the string b of length n. The string only consists of digits 0 and 1.It is guaranteed that the sum of n over all test cases doesn't exceed 3000.OutputFor each test case, if there is no way to make a equal to b, print -1. Otherwise, print the minimum cost needed to make a equal to b.ExampleInput
45 8 701001001015 7 201000110117 8 3011100101000015 10 10110001100Output
8
-1
6
0
NoteIn the first test case, selecting indices 2 and 3 costs 8, which is the minimum possible cost.In the second test case, we cannot make a equal to b using any number of operations.In the third test case, we can perform the following operations:  Select indices 3 and 6. It costs 3, and a is 0101011 now.  Select indices 4 and 6. It costs 3, and a is 0100001 now. The total cost is 6.In the fourth test case, we don't have to perform any operations.
45 8 701001001015 7 201000110117 8 3011100101000015 10 10110001100
8 -1 6 0 
['constructive algorithms', 'greedy', 'math', '*1400']