#include <bits/stdc++.h>
using namespace std;
int main() {
  char prev[26], next[26];
  for (int i = 0; i < 26; i++) prev[i] = next[i] = -1;
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    string s;
    cin >> s;
    if (prev[s[0] - 'a'] == -1) prev[s[0] - 'a'] = 0;
    if (next[s[(int)s.size() - 1] - 'a'] == -1)
      next[s[(int)s.size() - 1] - 'a'] = 0;
    for (int j = 1; j < (int)s.size(); j++) {
      prev[s[j] - 'a'] = s[j - 1];
      next[s[j - 1] - 'a'] = s[j];
    }
  }
  for (int i = 0; i < 26; i++) {
    if (prev[i] == 0) {
      char cur = 'a' + i;
      while (cur) {
        printf("%c", cur);
        cur = next[cur - 'a'];
      }
    }
  }
  return 0;
}
