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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 is given from Standard Input in the following format:

 $N$  $S$  $T$

Print the string formed.