#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;

int main() {
  int N; cin >> N;
  queue<int> que[N];
  for (int i = 0; i < N; i++) {
    int p; cin >> p;
    for (int j = 0; j < p; j++) {
      int x; cin >> x;
      que[i].push(x);
    }
  }
  vector<int> ans;
  while (true) {
    int cnt = 0;
    for (int i = 0; i < N; i++) {
      if (!que[i].empty()) {
        int x = que[i].front(); que[i].pop();
        ans.push_back(x);
      } else cnt++;
    }
    if (cnt >= N) break;
  }
  for (int i = 0; i < ans.size(); i++) cout << ans[i] << " \n"[i == ans.size() - 1];
  return 0;
}