import java.util.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		ArrayDeque<Integer>[] deqs = new ArrayDeque[n];
		for (int i = 0; i < n; i++) {
		    deqs[i] = new ArrayDeque<Integer>();
		    int p = sc.nextInt();
		    for (int j = 0; j < p; j++) {
		        deqs[i].add(sc.nextInt());
		    }
		}
		ArrayDeque<Integer> ans = new ArrayDeque<>();
		while (true) {
		    boolean flag = true;
		    for (int i = 0; i < n; i++) {
		        if (deqs[i].size() == 0) {
		            continue;
		        }
		        flag = false;
		        ans.add(deqs[i].poll());
		    }
		    if (flag) {
		        break;
		    }
		}
		StringBuilder sb = new StringBuilder();
		while (ans.size() > 0) {
		    sb.append(ans.poll());
		    if (ans.size() != 0) {
		        sb.append(" ");
		    }
		}
	    System.out.println(sb);
	}
}