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 Fortran (gfortran v4.8.4) (judge verdict: Accepted)

program bbb

implicit none
integer :: n, i, j
character(200) :: s, t, st

read*, n
read*, s, t
do i = 1, 200
st(i:i) = ' '
end do
s = trim(s)
t = trim(t)

j = 0
do i = 1, n
j = j + 1
st(j:j) = s(i:i)
j = j + 1
st(j:j) = t(i:i)
end do

write(*,*) trim(st)

end program