#include <bits/stdc++.h>
using namespace std;
using lint = long long;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;

int main() {
  cin.tie(nullptr); ios::sync_with_stdio(false);
  int n; cin >> n;
  V< queue<int> > qs(n);
  for (int i = 0; i < n; ++i) {
    int p; cin >> p;
    while (p--) {
      int a; cin >> a;
      qs[i].push(a);
    }
  }
  V<> res;
  while (true) {
    bool b = false;
    for (int i = 0; i < n; ++i) if (!qs[i].empty()) {
      res.push_back(qs[i].front());
      qs[i].pop();
      b = true;
    }
    if (!b) break;
  }
  int m = res.size();
  for (int i = 0; i < m; ++i) {
    cout << res[i] << " \n"[i == m - 1];
  }
}