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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
#include<algorithm>
#include<utility>
#include<vector>
#include<cmath>
using namespace std;

typedef pair<int, int> P;
typedef long long ll;
const int INF = 100000000;

ll gcd( ll a, ll b ){//最大公約数
    ll tmp;
    if( a < b ) { tmp = a; a = b; b = tmp; }
    if( b < 1 ) return -1;

    if( a % b == 0 ) return b;
    return gcd( b, a % b );
}

ll lcm(ll a, ll b){//最小公倍数
    return a * b / gcd(a, b);
}


//入力

int main(){

    string s, t;
    int n;
    cin >> n;
    cin >> s;
    cin >> t;

    string ans = "";

    for(int i=0; i < n; i++){
        ans += s[i];
        ans += t[i];
    }

    cout << ans << endl;

    return 0;
}