Strings with the Same Length

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

inputFormat

Input

Input is given from Standard Input in the following format:

N S T

outputFormat

Output

Print the string formed.

Examples

Input

2 ip cc

Output

icpc

Input

8 hmhmnknk uuuuuuuu

Output

humuhumunukunuku

Input

5 aaaaa aaaaa

Output

aaaaaaaaaa

样例

2
ip cc

icpc