You are given a string that contains only three characters $a$, $b$, and $c$. You can change at the most $k$ characters in the string. The uniformity index of a string is defined by the maximum length of the substring that contains the same character. Your task is to determine the maximum uniformity index than can be achieved.

Input format

• First line: Two integers $n$ and $k$ where $n$ denotes the size of the string and $k$ as specified in the question
• Second line: A string of length $n$

Output format
Print a single integer denoting the maximum uniformity that can be achieved.

Constraints
$1 \le N \le 10^6\\ 0 \le K \le N$
The string $s$ contains only characters $a$, $b$, and $c$.