#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (n); i++)
#define repr(i, n) for (int i = (n) - 1; i >= 0; i--)
#define range(a) a.begin(), a.end()

using namespace std;
using ll = long long;

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int N; cin >> N;
  vector<queue<int>> Q(N);
  rep(i, N) {
    int m; cin >> m;
    rep(_, m) {
      int x; cin >> x;
      Q[i].push(x);
    }
  }
  vector<int> ans;
  while (true) {
    bool upd = false;
    rep(i, N) {
      if (!Q[i].empty()) {
        ans.push_back(Q[i].front());
        Q[i].pop();
        upd = true;
      }
    }
    if (!upd) break;
  }
  for (int x : ans) cout << x << ' ';
  cout << endl;
}