Score : $300$ points
You are given a string $S$ of length $N$ and another string $T$ of length $M$. These strings consist of lowercase English letters.
A string $X$ is called a good string when the following conditions are all met:
Determine if there exists a good string. If it exists, find the length of the shortest such string.
Input is given from Standard Input in the following format:
$N$ $M$ $S$ $T$
If a good string does not exist, print
-1; if it exists, print the length of the shortest such string.
3 2 acp ae
For example, the string
accept is a good string.
There is no good string shorter than this, so the answer is $6$.
6 3 abcdef abc
15 9 dnsusrayukuaiia dujrunuma