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 <iostream>
#include <string>
#include <vector>
using namespace std;

int main()
{
  int N;
  cin >> N;
  string s;
  string t;

  cin >> s;
  cin >> t;

  string sub;
  int kasa=0;
  for(int i=0; i < N; i++){
    sub = s.substr(i, N-i);
    if(sub == t.substr(0, N-i)) kasa = N-i;
  }
  int ans = s.size() + t.size() - kasa;

  cout << ans << endl;
  return 0;
}