Problem Statement

Snuke is interested in strings that satisfy the following conditions:

• The length of the string is at least $N$.
• The first $N$ characters equal to the string $s$.
• The last $N$ characters equal to the string $t$.

Find the length of the shortest string that satisfies the conditions.

Constraints

• $1≤N≤100$
• The lengths of $s$ and $t$ are both $N$.
• $s$ and $t$ consist of lowercase English letters.

Input

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

N
s
t

Output

Print the length of the shortest string that satisfies the conditions.