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 <bits/stdc++.h>

using namespace std;

#define rep(i, n) for(int i = 0; i < (int)n; ++i)
#define FOR(i, a, b) for(int i = a; i < (int)b; ++i)

typedef long long ll;

const int Inf = 1e9;
const double EPS = 1e-9;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n, len;
    string s, t;
    cin >> n >> s >> t;
    int res = 2 * n;
    rep (i, n) {
        string u, v;
        u = s.substr(i, n - i);
        v = t.substr(0, n - i);
        if (u == v) {
            res -= n - i;
            break;
        }
    }
    cout << res << endl;
    
    return 0;
}