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 Pascal (FPC 2.6.2) (judge verdict: Wrong Answer)

uses crt;
var
        n,d,i,j:byte;
        t,a,b,c:string;
begin

        clrscr;
        readln(n);
        readln(t);
        for i:=1 to n do if t[i]<>' ' then a:=a+t[i];
        for j:=1 to n do  b:=b+t[i+j+1];
        i:=0;
        while i<>n do
        begin
                if (d=0) then
                begin
                        inc(i);
                        c:=c+a[i];
                        inc(d);
                end;
                if (d=1) then
                begin
                        c:=c+b[i];
                        dec(d);
                end;
        end;
        write(c);
        readln;
end.