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 <string>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  int N;
  string s, t;
  cin >> N >> s >> t;
  for (int i = 0; i < s.size(); ++i) {
    const auto sub = s.substr(i);
    if (sub == t.substr(0, t.size() - i)) {
      cout << s.size() + t.size() - sub.size() << endl;
      return 0;
    }
  }
  cout << s.size() + t.size() << endl;

  return 0;
}