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.Linq;
using System.Collections.Generic;
using System.IO;
using static System.Console;


namespace atcorder2
{
    class Program
    {
        public static long Read()
        {

            return long.Parse(Console.ReadLine());
        }

        public static long[] Reads()
        {

            return Console.ReadLine().Split().Select(long.Parse).ToArray();
        }

       
         public static long GCM(long x,long y)
        {
            if (x < y)  GCM(y, x);


            while (y > 0)
            {
                var z = y;
                y = x % y;
                x = z;
            }
            
            return x;
        }

        



        static void Main(string[] args)
        {
            var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            Console.SetOut(sw);


            var n = Read();
            var s = ReadLine();
            var t = ReadLine();
            long ans = 0;
            bool f=true;
            for (int i = 0; i < n; i++)
            {
                f = true;
                for (int j = i; j < n-i; j++)
                {
                    if (t[j - i] != s[j]) f = false;
                }
                if (f) { ans = i; break; }
            }
            WriteLine(f ? n+ans : n+ans + 1);
            
            
           










            Console.Out.Flush();
        }
    }
}