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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

package atcoder;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
//		int    N = scan.nextInt();
//		String S = scan.next();
//		String T = scan.next();
		int N = 2;
		String S = "aa";
		String T = "bb";
		List <String> list = new ArrayList<>();

		for (int i = 0; i < N; i++) {
			list.add(String.valueOf(S.charAt(i)));
			list.add(String.valueOf(T.charAt(i)));
		}
		for (int i=0; i <  list.size(); ++i)
		{
		    System.out.print(list.get(i));
		}
	}
}