Problem Statement

You are given strings $S$ and $T$ of length $N$ consisting of lowercase English letters.

You can repeat the following operation any number of times (possibly zero).

• Erase the first character of $S$ and insert the same character at any position of $S$.

Determine whether it is possible to make $S$ equal $T$, and if it is possible, find the minimum number of operations needed.

Constraints

• $1 \le N \le 2 \times 10^5$
• $S$ and $T$ are strings of length $N$ consisting of lowercase English letters.

Input

The input is given from Standard Input in the following format:

N
S
T

Output

If it is impossible to make $S$ equal $T$, print -1. If it is possible, print the minimum number of operations needed.