#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n;
  cin >> n;

  vector<vector<int> > vs;
  int cnt = 0;
  REP (i, n) {
    int m;
    cin >> m;
    cnt = max(cnt, m);
    vector<int> v(m);
    REP (j, m) cin >> v[j];
    vs.push_back(v);
  }

  REP (i, cnt) {
    REP (j, n) {
      if (i < vs[j].size())
        cout << vs[j][i] << " ";
    }
  }
  cout << endl;
  
  return 0;
}