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Contest: Task: Related: TaskB

Score : $200$ points

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.