import java.util.*;

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