B'Kristina has a string s of length n , consisting only of lowercase and uppercase Latin letters. For each pair of lowercase letter and its matching uppercase letter, Kristina can get 1 burl. However, pairs of characters cannot overlap, so each character can only be in one pair. For example, if she has the string s = "aAaaBACacbE", she can get a burl for the following character pairs: Kristina wants to get more burles for her string, so she is going to perform no more than k operations on it. In one operation, she can: For example, when k = 2 and s = "aAaaBACacbE" it can perform one operation: choose s_3 = "a" and make it uppercase. Then she will get another pair of s_3 = "A" and s_8 = "a" Find maximum number of burles Kristina can get for her string. The first line of input data contains a single integer t ( 1 <= t <= 10^4 ) -- the number of test cases. The description of the test cases follows. The first line of each test case contains two integers n ( 1 <= n <= 2 cdot 10^5 ) and k ( 0 <= k <= n ) -- the number of characters in the string and the maximum number of operations that can be performed on it. The second line of each test case contains a string s of length n , consisting only of lowercase and uppercase Latin letters. It is guaranteed that the sum of n over all test cases does not exceed 2 cdot 10^5 . For each test case, print exactly one integer on a separate line: the maximum number of burles that Kristina can get for her string s . The first test case is explained in the problem statement. In the second test case, it is not possible to get any pair by performing any number of operations. '...