#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>

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; }

const long long MAX = 510000;
const long long INF = 1LL << 60;
const long long MOD = 1000000007LL;

using namespace std;
typedef unsigned long long ull;
typedef  long long ll;


int main()
{
	ll N;
	cin >> N;
	vector<queue<ll>> vq(N);
	for (ll i = 0; i < N; i++) {
		ll p;
		cin >> p;
		for (ll j = 0; j < p; j++) {
			ll a;
			cin >> a;
			vq[i].push(a);
		}
	}
	vector<ll> res;
	while (1) {
		bool flag = false;
		for (ll i = 0; i < N; i++) {
			if (!vq[i].empty()) {
				res.push_back(vq[i].front());
				flag = true;
				vq[i].pop();
			}
		}
		if (!flag) {
			break;
		}
	}

	for (ll i = 0; i < res.size(); i++) {
		cout << res[i];
		if (i == (ll)res.size() - 1) {
			cout << endl;
		}
		else {
			cout << " ";
		}
	}
	return 0;
}