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

int main()
{
	int N;
	cin >> N;
	vector<queue<int>> A( N );
	for( int i = 0; i < N; i++ ) {
		int P;
		cin >> P;
		for( int j = 0; j < P; j++ ) {
			int a;
			cin >> a;
			A[i].push( a );
		}
	}

	vector<int> ans;
	int flag = 1;
	while( flag ) {
		flag = 0;
		for( int i = 0; i < N; i++ ) {
			if( A[i].empty() ) continue;
			int a = A[i].front();
			A[i].pop();
			ans.push_back( a );
			flag = 1;
		}
	}

	for( int i = 0; i < ans.size(); i++ ) {
		if( i ) cout << " ";
		cout << ans[i];
	}
	cout << endl;
}