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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include "stdio.h"
#include "stdlib.h"

int main(void)
{
  char buff[5];
  size_t n = (size_t)atoi(fgets(buff, sizeof buff, stdin))+1;

  char *s = fgets(malloc(n+1), n, stdin);
  char *t = fgets(malloc(n+1), n, stdin);

  for (int i = 0; i < n || !s[i]; i++) {
    putc(s[i], stdout);
    putc(t[i], stdout);
  }

  free(s);
  free(t);
  return 0;
}