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.

Examples

Input

2
ip cc

Output

icpc

Input

8
hmhmnknk uuuuuuuu

Output

humuhumunukunuku

Input

5
aaaaa aaaaa

Output

aaaaaaaaaa

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