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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.