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# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Text;
using System.Collections.Generic;
using System.Collections;
using static System.Math;
using System.Linq;
using static System.Array;

namespace ConsoleApp2
{
    class Program
    {

        static void Main(string[] args)
        {
            var N = long.Parse(Console.ReadLine());
            //var NMX = Console.ReadLine().Split(' ').Select(x => double.Parse(x)).ToArray();
            var s = Console.ReadLine();
            var t = Console.ReadLine();
            var OK = true;
            var ans = 2 * N;
            for (int i = 0; i < N; i++)
            {
                OK = true;
                for (int j = 0; j <= i; j++)
                {
                    if (t[j] != s[(int)N-1+j-i])
                    {
                        OK = false;
                    }
                }

                if (OK) ans = Min(ans, 2 * N-(i+1));


            }

            Console.WriteLine(ans);
            
        }


    }

}