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 Perl6 (rakudo-star 2016.01) (judge verdict: Accepted)

use v6;
my $n = get().chomp;
my $str1 = get().chomp;
my $str2 = get().chomp;
my $ans = $n * 2;
loop (my $i = 0; $i < $n; $i++) {
	my $s1 = $str1.substr($i);
	my $s2 = $str2.substr(0, $n - $i);
	if $s1 eq $s2 {
		$ans = $n + $i;
		last;
	}
}
say $ans;

exit;