Hiho! is a serial contests we developed to help programmers improve their skills following some architecture. And for the beginning of this serial, we presents the "String". Dealing with the string is very common when you programming in real world. Although we usually use the standard methods to deal with them, these standard methods contains a lot of brilliant idea inside of it. So we think it's a good idea to hiho some typical string problems to all you, it'll help your programming thinking.

And this problem "KMP" introduces a classic solution to "Pattern Matching" prolem(Judging if a string is a substring of another string), its idea is very simply but creative, so those who has't learnt before better listen carefully to Hi's speech~

After the end of this contest, we will publish the source code of little HO and all the participants that solved this problem. Wish you learn from each other and make improvement togather!