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: Accepted)

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

using namespace std;

typedef long long ll;

int main() {
    int n;
    string s, t;
    cin >> n >> s >> t;

    string ans = "";
    for (int i = 0; i < n; ++i) {
        if (s.substr(i, n - i) == t.substr(0, n - i)){
            break;
        }else{
            ans.push_back(s[i]);
        }
    }

    ans += t;

    cout << ans.size() << endl;
}