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;


namespace tst
{
    class Program
    {
        public static void Main()
        {
            int n = int.Parse(Console.ReadLine());
            string[] x= Console.ReadLine().Split(' ');
            string s = x[0];
            string t = x[1];
            bool flag = true;//boolでsとt交互に表示
            for (int i = 0; i < 2*n; i++){
                if (flag)
                {//偶数番目
                    Console.Write(s[i / 2]);
                    flag = false;
                }
                else
                {//奇数番目
                    Console.Write(t[(i - 1) / 2]);
                    flag = true;
                }
            }
            Console.WriteLine();
        }

    }
}