#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <fstream>
#include <chrono>
#include <random>
#include <bitset>
//#include <atcoder/all>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)(x).size())
#define pb push_back
using ll = long long;
using namespace std;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}

int main(){
  int N; cin >> N;
  vector<queue<int>> Q(N);
  rep(i,N){
    int n; cin >> n;
    while(n--){
      int a; cin >> a;
      Q[i].push(a);
    }
  }
  vector<int> ans;
  int flag = 1;
  while(flag){
    flag = 0;
    rep(i,N){
      if(!Q[i].empty()){
        ans.pb(Q[i].front()); Q[i].pop();
        flag=1;
      }
    }
  }
  rep(i,sz(ans)){
    if(i) cout << ' ';
    cout << ans[i];
  }
  cout << endl;
  return 0;
}