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 int;

int main(void) {
    cin.tie(0); ios::sync_with_stdio(false);
    ll n;
    cin >> n;
    string s, t;
    cin >> s >> t;

    for(ll i=0; i<=n; i++) {
        bool ok = true;
        for(ll j=0; j<n && i+j<n; j++)
            ok &= s[i+j] == t[j];
        if(ok) {
            for(ll j=0; j<i; j++)
                cout << s[j];
            cout << t << endl;
            return 0;
        }
    }
}