#include <bits/stdc++.h>
using namespace std;
char ch[1000];
bool used[1000];
bool notst[1000];
int main() {
  int n, i, j;
  string s;
  char c, chr;
  cin >> n;
  for (c = 'a'; c <= 'z'; c++) ch[c] = '#';
  for (i = 0; i < n; i++) {
    cin >> s;
    for (j = 0; j < s.length() - 1; j++) {
      ch[s[j]] = s[j + 1];
      used[s[j]] = true;
      notst[s[j + 1]] = true;
    }
    used[s[s.length() - 1]] = true;
    if (ch[s[s.length() - 1]] == '#') ch[s[s.length() - 1]] = s[s.length() - 1];
  }
  for (c = 'a'; c <= 'z'; c++)
    if (!notst[c] && used[c]) {
      chr = c;
      while (ch[chr] != chr) {
        cout << chr;
        chr = ch[chr];
      }
      cout << chr;
    }
  return 0;
}
