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 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
#include <string.h>
#define rep(i,n) for(int i=0; i<(int)(n); i++)

int main(){
    int n; scanf("%d",&n);
    char s[105],t[105]; scanf("%s%s",s,t);
    int ans=2*n;
    rep(i,n+1){
        if(i==0)continue;
        char st[105]={0},tt[105]={0};
        strncpy(st,s+n-i,i);
        strncpy(tt,t,i);
        if(strcmp(st,tt)==0) ans=2*n-i;
    }
    printf("%d\n",ans);
}