Problem:
Score : 200 points

Problem Statement

Given are strings s and t of length N each, both consisting of lowercase English letters.

Let us form a new string by alternating the characters of S and the characters of T, as follows: the first character of S, the first character of T, the second character of S, the second character of T, ..., the N-th character of S, the N-th character of T. Print this new string.

Constraints

1 \leq N \leq 100

|S| = |T| = N

S and T are strings consisting of lowercase English letters.

Input

Input is given from Standard Input in the following format:

N
S T

Output

Print the string formed.

Sample Input 1

2
ip cc

Sample Output 1

icpc

Sample Input 2

8
hmhmnknk uuuuuuuu

Sample Output 2

humuhumunukunuku

Sample Input 3

5
aaaaa aaaaa

Sample Output 3

aaaaaaaaaa

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

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

public class Program
{
    static void Main()
    {
        string line = Console.ReadLine().Trim();

        string[] lineRecord = Console.ReadLine().Trim().Split(' ');

        var answer = string.Empty;
        for (int i = 0; i < int.Parse(line); i++)
        {
            if (string.IsNullOrEmpty(answer))
            {
                answer = lineRecord[0].Substring(0, 1) + lineRecord[1].Substring(0, 1);
            }
            else
            {
                answer += lineRecord[0].Substring(i, 1) + lineRecord[1].Substring(i, 1);
            }
        }

        Console.WriteLine(answer);
    }
}