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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod=1e9+7;

int main(){
    int N, ans=1;
    string s, t, str, astr;
    cin >> N >> s >> t;
    for(int i=0; i<s.size(); i++){
        if(s[i]==t[0]){
            for(int j=0;i<s.size()-i;j++){
                if(s[j+i]!=t[j]){
                    break;
                }
            }
            ans = i;
        }
    }
    for(int j=0;j<ans;j++){
        astr += s[j];
    }
    astr += t;
    cout << astr.size();
}