A string contains only 'j' and 'z'. You can perform the operation of swapping any two characters at most K times. What is the maximum number of appearance times of substring "jz" after at most K operations?

First line contains N and K, indicating the length of string and the largest number of swapping.( 1<=N<=500, 0<=K<=100 )

Second line contains a string only contains lowercase characters 'j' and 'z'.

The maximum appearance times.

5 2
zzzjj

2

First step, change the string to jzzzj.

Second step, change it to jzzjz.

Finally, you'll get two substring of "jz" in jzzjz.