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# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
class Program{
  static string s;
  static string t;
  static int n;
  static bool JUDGE(int m){
    bool f = true;
    for (int i = 0;i < m;i++)
      f = f && s[n-m+i] == t[i];
    return f;
  }
  static void Main(){
    n = int.Parse(Console.ReadLine());
    s = Console.ReadLine();
    t = Console.ReadLine();
    for (int i = n;i >= 0;i--){
      if (JUDGE(i)){
        Console.WriteLine(2 * n - i);
        break;
      }
    }
  }
}