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.

Sample Input 1

3
abc
cde

Sample Output 1

5

The shortest string is abcde.

Sample Input 2

1
a
z

Sample Output 2

2

The shortest string is az.

Sample Input 3

4
expr
expr

Sample Output 3

4

The shortest string is expr.