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)

//Giorgi Kldiashvili

#include <bits/stdc++.h>

#define ll long long
#define M 1000000007LL

using namespace std;

int n;
string a, b;

int main()
{
  cin >> n;
  cin >> a >> b;

  for(int i = 0; i < n; ++ i)
  {
    for(int j = 0; j < n; ++ j)
    {
      if(i + j == n)
      {
        cout << i + n << endl;
        return 0;
      }
      if(a[i + j] != b[j])
        break;
    }
  }
  cout << n + n << endl;
}