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>

int main(void){
	int i,j,N,result=-1;

	scanf("%d",&N);

	char s[N+1],t[N+1];

	scanf("%s",s);
	scanf("%s",t);
	
	for(i=0;i<N;i++){
		if(s[i]==t[0]){
			for(j=i;j<N;j++){
				if(s[j]!=t[j-i]){
					result = -1;
					break;
				}
				result = i;
			}
		}
	}
	
	if(result!=-1){
	printf("%d",N+result);
	} else {
		printf("%d",2*N);
	}
	return 0;
}