#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define printVec(v) printf("{"); for (const auto& i : v) { std::cout << i << ", "; } printf("}\n");
#define degreeToRadian(deg) (((deg)/360)*2*M_PI)
#define radianTodegree(rad) (((rad)/2/M_PI)*360)
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
using namespace std;
using P = pair<int,int>;
using ll = long long;
const ll INF = 1LL<<60;
const int MOD = 1e9 + 7;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

//cin.tie(0);ios::sync_with_stdio(false);
//cout << fixed << setprecision(15) << y << endl;
int main() {
  int n;
  cin >> n;
  vector<queue<int>> que(n);
  rep (i, n) {
    int p;
    cin >> p;
    rep (j, p) {
      int a;
      cin >> a;
      que[i].push(a);
    }
  }

  vector<int> ans;
  bool ok = true;
  while (ok) {
    ok = false;
    rep (i, n) {
      if (que[i].empty()) continue;
      ok = true;
      cout << que[i].front() << " ";
      que[i].pop();
    }
  }
  return 0;
}