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 (GCC 5.4.1) (judge verdict: Wrong Answer)

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

int N;
int tmp = 0, ans;
char s[112], t[112];

int main() {
	scanf("%d", &N);
	scanf("%s", &s);
	scanf("%s", &t);
	if (strcmp(s, t) != 0) {
		for (int i = 0; i < N; ++i) {
			if (s[N - i - 1] == t[i]) {
				tmp++;
			}
		}
		ans = strlen(s) + strlen(t);
		ans -= tmp;
	}
	else {
		ans = N;
	}

	printf("%d\n", ans);
	return 0;
}