Problem:
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.

Solution in Perl (v5.18.2) (judge verdict: Accepted)

use v5.18; # strict say state
use warnings;
use List::Util qw(reduce first max min sum0);

chomp (my $n = <STDIN>);
chomp (my $s = <STDIN>);
chomp (my $t = <STDIN>);
for my $i (0..($n-1)) {
  if (substr($s, $i, $n-$i) eq substr($t, 0, $n-$i)) {
    say $n + $i;
    exit;
  }
}
say 2 * $n;