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: Accepted)

#include<stdio.h>
#include<stdlib.h>

int main(){
    int n=0, i, j;
    char *s, *t;

    scanf("%d", &n);
    if(n>100 || n<0){
        printf("nが正しくないです\n");
        return 1;
    }

    s = (char *)malloc(sizeof(char)*n);
    t = (char *)malloc(sizeof(char)*n);
    if(s==NULL || t==NULL){
         printf("文字列を確保できませんでした\n");
         return 1;
    }

    scanf("%s", s);
    scanf("%s", t);

    for(i=0;i<n;i++){
        for(j=0;j<n-i;j++){
            if(s[i+j]!=t[j]){
                break;
            }
        }
        if(j==n-i)
            break;
    }

    printf("%d\n", i+n);

    free( s );
    free( t );

    return 0;
}