Lonely Y loves his string $s$ of lowercase letters, Y is about to escape so he should choose just one lowercase letter $c$ and carry all letters in $s$ which is equal to $c$ with himself.

What is the maximum number of letters Y can carry with himself?

Input

First line contains only $n$, legnth of string $s$.

Second line contains string $s$ of lowercase letters.

$1 \leq n \leq 10^5$

Output

The only line of output contains an integer which is maximum number of letters that Y can carry.