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 C (Clang 3.8.0) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<string.h>

int main() {
	char s[101], t[101];
	int N;
	int loop;
	int len;
	int Ls;

	scanf("%d", &N);
	scanf("%s %s", s, t);

	len = strlen(s) + strlen(t);
	Ls = strlen(s);
	for (loop = 0; loop < N; loop++) {
		if (s[Ls - loop - 1] == t[loop])len--;
		else break;
	}
	printf("%d\n", len);
	return 0;
}