import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.List;
import java.util.Queue;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		int cnt = 0;
		List<Queue<Integer>> list = new ArrayList<>(n);
		for (int i = 0; i < n; i++) {
			Queue<Integer> que = new ArrayDeque<>();
			list.add(que);
			String[] sa = br.readLine().split(" ");
			if (Integer.parseInt(sa[0]) == 0) {
				cnt++;
			}
			for (int j = 1; j < sa.length; j++) {
				que.add(Integer.parseInt(sa[j]));
			}
		}
		br.close();

		StringBuilder sb = new StringBuilder();
		while (cnt < n) {
			for (int i = 0; i < n; i++) {
				Queue<Integer> que = list.get(i);
				if (!que.isEmpty()) {
					sb.append(que.poll()).append(' ');
					if (que.isEmpty()) {
						cnt++;
					}
				}
			}
		}
		sb.deleteCharAt(sb.length() - 1);
		System.out.println(sb.toString());
	}
}