Five string training

https://www.luogu.org/problem/P3435

This topic of toxic Chinese translation

First translate topics:

• If there string B (B may be empty), so that A = PB, then A is a prefix of said P.
• If A! = P A and P is the prefix, then P is called the A proper prefix.
• If Q is a proper prefix A, and A is QQ prefix, then known as Q is the period of A.
• If Q is in all cycles A maximum length that, then known as Q is the maximum period of A. Particular, if the cycle A does not exist, then the maximum period A is an empty string.
• Given a string S, the maximum period required all prefixes of S and length.
  Reinstall the system. . . . . To be continued