#include <bits/stdc++.h>

int ri() {
	int n;
	scanf("%d", &n);
	return n;
}
int main() {
	int n = ri();
	std::vector<int> a[n];
	for (int i = 0; i < n; i++) {
		a[i].resize(ri());
		for (auto &j : a[i]) j = ri();
		std::reverse(a[i].begin(), a[i].end());
	}
	std::vector<int> res;
	for (;;) {
		bool cont = false;
		for (int i = 0; i < n; i++) {
			if (a[i].size()) res.push_back(a[i].back()), a[i].pop_back(), cont = true;
		}
		if (!cont) break;
	}
	for (auto i : res) std::cout << i << " ";
	std::cout << std::endl;
	
	return 0;
}