#include<bits/stdc++.h>
using namespace std;
int main(){
    char c;
    int n; cin >> n;
    while(n--) cin >> c, cout << c << c;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main() {
   int N;
   string S;
   cin >> N >> S;
   for (int i = 0; i < N; i++) {
      cout << S[i] << S[i];
   }
   cout << endl;
}