#include <bits/stdc++.h>
using namespace std;

int main() {
  int N;
  cin >> N;
  vector<queue<int>> A(N);
  bool check = true;
  int max_queue = 0, max_size = INT_MIN;
  
  for (int i = 0; i < N; i++) {
    int P;
    cin >> P;
    for (int j = 0; j < P; j++) {
      int a;
      cin >> a;
      A.at(i).push(a);
    }
    if ((int)A.at(i).size() >= max_size) {
      max_queue = i;
      max_size = A.at(i).size();
    }
  }
  
  while (check) {
    check = false;
    for (int i = 0; i < N; i++) {
      if (!A.at(i).empty()) {
        check = true;
        cout << A.at(i).front();
        A.at(i).pop();
        if(!A.at(max_queue).empty())
          cout << ' ';
      }
    }
  }
  cout << endl;
}