Problem Description

Given a string of length $L$, you need to find the longest substring that appears at least twice in the string (at different positions). Output its length.

Input Format

The first line contains an integer $L$, representing the length of the string.

The second line contains a string of length $L$.

Output Format

Output one line containing one integer, representing the length of this longest substring.

11
sabcabcfabc

3

18
trutrutiktiktappop

4

6
abcdef

0

Hint

Constraints

For $100\%$ of the testdata, it is guaranteed that $1 \le L \le 2 \times 10^5$, and the input string consists only of lowercase letters.

Notes

This problem is translated from COCI2006-2007 CONTEST #5 T6 DVAPUT.

Translated by ChatGPT 5