Problem Description

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

Input Format

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

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

Output Format

Output a single integer, representing the length of the longest substring that appears at least twice.

Sample Input and Output

Sample Input #1

11
sabcabcfabc

Sample Output #1

3

Sample Input #2

18
trutrutiktiktappop

Sample Output #2

4

Sample Input #3

6
abcdef

Sample Output #3

0

Notes

Data Size and Constraints

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

Note

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

见题面 Input 部分

见题面 Output 部分