#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>

std::vector<char> g_priority[26] = {};
bool g_visited[26] = {};

void PrintOrder(int cur);

int main() {
  char prev[21] = {};
  while (std::scanf("%s", prev) != EOF) {
    for (int i = 0; i < 26; ++i) {
      g_priority[i].clear();
    }
    std::memset(g_visited, 0, sizeof(g_visited));

    bool check[26] = {};
    while (true) {
      char cur[21] = {};
      std::scanf("%s", cur);
      if (cur[0] == '#') {
        break;
      }
      std::size_t len = std::min(std::strlen(prev), std::strlen(cur));
      for (std::size_t i = 0; i < len; ++i) {
        int p = prev[i] - 'A', c = cur[i] - 'A';
        check[p] = check[c] = true;
        if (p != c) {
          g_priority[c].push_back(p);
          break;
        }
      }
      for (std::size_t i = 0; i <= strlen(cur); ++i) {
        prev[i] = cur[i];
      }
    }

    for (int i = 0; i < 26; ++i) {
      if (check[i] == true) {
        PrintOrder(i);
      }
    }

    std::puts("");
  }
  return EXIT_SUCCESS;
}

void PrintOrder(int cur) {
  if (g_visited[cur] == false) {
    for (std::size_t i = 0; i < g_priority[cur].size(); ++i) {
      PrintOrder(g_priority[cur][i]);
    }
    std::putchar(cur + 'A');
    g_visited[cur] = true;
  }
}