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 (Clang 3.8.0) (judge verdict: Accepted)

#include <iostream>

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

    for (int i = 0; i <= n; i++) {
        int j = 0;
        for (j = 0; j < n - i; j++) {
            if (s[j+i] != t[j]) {
                break;
            }
        }
        if (j >= n - i) {
            std::cout << (n - i) + i * 2 << std::endl;
            return 0;
        }
    }
    return 0;
}