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;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
using System.Text.RegularExpressions;
using System.Linq;

class Magatro
{

    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        string s = Console.ReadLine();
        string t = Console.ReadLine();
        for(int i = 0; i < N; i++)
        {
            string a = s.Substring(i);
            string b = t.Substring(0, N  - i);
            //Console.WriteLine(a + " " + b);
            if (a == b)
            {
                Console.WriteLine(N * 2 - a.Length);
                return;
            }
        }
        Console.WriteLine(N * 2);
    }

}