#include <iostream>
#include <vector>
#include <queue>
using namespace std;
int main(){
	int N;
	cin >> N;
	vector<queue<int>> Q(N);
	for (int i = 0; i < N; i++){
		int P;
		cin >> P;
		for (int j = 0; j < P; j++){
			int A;
			cin >> A;
			Q[i].push(A);
		}
	}
	vector<int> ans;
	while (1){
		bool upd = false;
		for (int i = 0; i < N; i++){
			if (!Q[i].empty()){
				ans.push_back(Q[i].front());
				Q[i].pop();
				upd = true;
			}
		}
		if (!upd){
			break;
		}
	}
	int T = ans.size();
	for (int i = 0; i < T; i++){
		cout << ans[i];
		if (i < T - 1){
			cout << ' ';
		}
	}
	cout << endl;
}