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.

Input

Input is given from Standard Input in the following format:
N
S T

Output

Print the string formed.

Constraints

• $1 \leq N \leq 100$
• |S| = |T| = N
• S and T are strings consisting of lowercase English letters.

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

见题面 Input 部分

见题面 Output 部分