SOLVE
LATER
For a given integer K and a string S of length N, we denote power of S, as the length of a longest substring occurring in S at least K times.
Given K and S, find the power of S.
Constraints:
1 <= N <= 10^{6}
1 <= K <= N
S consists of latin lowercase letters only
Input format:
In the first line there are two integers K and N separated by a single space. The second line constains string S itself.
Output format:
In one line, output the power of string S for a given K.
Substring "abra" occurs in S two times and it is the longest substring of all substrings of S occurring at least two times.