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 ABC148B
    integer N
    character(100) S,T
    character(200) ans
    read*,N
    read*,S,T
    ans=""
    do i=1,N
        ans(2*i-1:2*i-1)=S(i:i)
        ans(2*i:2*i)=T(i:i)
    end do
    print"(A)",trim(ans)
end program