- Time limit: 1.00 s
- Memory limit: 512 MB
A repeating substring is a substring that occurs in two (or more) locations in the string. Your task is to find the longest repeating substring in a given string.
The only input line has a string of length n that consists of characters a–z.
Print the longest repeating substring. If there are several possibilities, you can print any of them. If there is no repeating substring, print -1.
- 1 \le n \le 10^5