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: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;




namespace contest
{

    class contest
    {


        static void Main(string[] args)
        {


            //int n = int.Parse(Console.ReadLine());
            //var input = Console.ReadLine().Split().Select(int.Parse).ToArray();


            int n = int.Parse(Console.ReadLine());
            string s = Console.ReadLine();
            string t = Console.ReadLine();


            int length = s.Length+t.Length;

            for(int i =0; i<s.Length && i<t.Length; i++)
            {
                if(s[s.Length-1-i] == t[i])
                {
                    length--;
                }

            }

            if (length < n) length = n;
            if (s.CompareTo(t) == 0) length = s.Length;
            Console.WriteLine(length);


            //Console.Read();


        }

        


    }


}