#include <iostream>
#include <cstdio>
#include <cstring>
#define NMAX 18
#define LMAX 30000

using namespace std;

int n;
int urm[2 * LMAX + 5], l[NMAX + 1];
int pref[NMAX + 1][NMAX + 1];
int d[(1 << NMAX) + 1][NMAX + 1][2]; /// tin minte si de unde am venit
char s[NMAX + 1][LMAX + 5];
char p[2 * LMAX + 10];

int prefix(char *pattern, int lp) {
  int k, bestk = 0;

  urm[0] = 0;
  for(int i = 1; i < lp; i++) {
    k = urm[i - 1];
    while(k > 0 && pattern[i] != pattern[k])
      k = urm[k - 1];
    if(pattern[i] == pattern[k])
      k++;
    urm[i] = k;
  }
  return urm[lp - 1];
}

void get_adn(int ind, int bm) {
  if(d[bm][ind][1] == -1)
    printf("%s", s[ind]);
  else {
    int old_bm = bm ^ (1 << ind), dad = d[bm][ind][1], old_l = d[old_bm][dad][0], crt_l = d[bm][ind][0], lind = l[ind];
    get_adn(dad, old_bm);
    printf("%s", s[ind] + lind - crt_l + old_l);
  }
}

bool inside(int ind1, int ind2) {
  int l2 = l[ind2], l1 = l[ind1];
  int aux = prefix(s[ind2], l2), k = 0;

  for(int i = 0; i < l1; i++) {
    while(k > 0 && s[ind1][i] != s[ind2][k])
      k = urm[k - 1];
    if(s[ind1][i] == s[ind2][k])
      k++;
    if(k == l2)
      return true;
  }
  return false;
}

void elim(int ind) {
  for(int i = ind; i < n; i++)
    swap(s[i], s[i + 1]), swap(l[i], l[i + 1]);
  n--;
}

int main() {
  freopen("adn.in", "r", stdin);
  freopen("adn.out", "w", stdout);
  int pn;

  scanf("%d ", &n);
  for(int i = 0; i < n; i++) {
    scanf("%s", &s[i]);
    l[i] = strlen(s[i]);
  }
  for(int i = 0; i < n; i++)
    for(int j = 0; j < n; j++)
      if(j != i && inside(i, j)) /// daca j se afla in interiorul lui i
        elim(j--);
  pn = 1 << n;

  for(int i = 0; i < n; i++) {
    int li = l[i];
    strncpy(p, s[i], li);
    p[li] = '#';
    for(int j = 0; j < n; j++) {
      if(i == j)
        continue;
      int lj = l[j];
      strncpy(p + li + 1, s[j], lj);
      p[li + lj + 1] = NULL;
      pref[j][i] = prefix(p, li + lj + 1);
    }
  }

  for(int bm = 1; bm < pn; bm++)
    for(int i = 0; i < n; i++)
      if(bm & (1 << i)) {
        int nbm = bm ^ (1 << i), li = l[i];

        if(nbm == 0)
          d[bm][i][0] = li, d[bm][i][1] = -1;
        else
          for(int j = 0; j < n; j++)
            if(nbm & (1 << j)) {
              int lj = l[j];
              if(d[bm][i][0] == 0 || d[nbm][j][0] - pref[j][i] + li < d[bm][i][0]) {
                d[bm][i][0] = d[nbm][j][0] - pref[j][i] + li;
                d[bm][i][1] = j;
              }
            }
      }

  int minim = 18 * LMAX + 5, pozmin = 0;
  for(int i = 0; i < n; i++)
    if(d[pn - 1][i][0] != 0 && d[pn - 1][i][0] < minim)
      minim = d[pn - 1][i][0], pozmin = i;
  get_adn(pozmin, pn - 1);

  return 0;
}