Longest Border

Difficulty: 1500 2000 ms 128 MB

strings

A border of S is a string that is both a proper prefix and a proper suffix of S. Print the length of the longest border (0 if none).

Input: one line with a lowercase string.

Output: the longest border length.

Constraints:

• 1 ≤ |S| ≤ 10⁴

Sample Tests

abcab

2

aaaa

3

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