#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)

int main(void)
{
  int n; cin >> n;
  vector<string> s(n);
  rep(i, n) cin >> s[i];
  rep(i, n) cout << s[i];
  cout << '\n';
  return 0;
}