#include <iostream>
#include <stdio.h>
#include <string>
#include <vector>
#include <set>
#include <cmath>
#include <algorithm>
#define MP make_pair
using ll = long long;
using namespace std;

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