Chandler is given a task by his boss. He is given a string S of length N which only has ‘x’ & ‘y’. He can change the maximum of C alphabets in the given string. Finally, He has to tell his boss the maximum length of a substring consisting of numofchar(x) == numofchar(y). In a single change he can change 'x'to'y' or 'y' to 'x'.
Since he wants to go out with his F.R.I.E.N.D.S. Can you tell him the answer?
Constraints :
Input Format :
First line contains number of testcases T.
First line of each testcase contains two numbers N and C,length and maximum replacable characters.
Second line of each testcase contains string S.
Output Format:
Print the single interger per testcases denoting maximum length of substring.
He can change 5th character to y and then substring from index 2 to index 7 will be of length 6 containing the equal number of x and y character. (considering 1 based indexing)