#include <stdio.h>

int main(){
	int cashier = 0;
	scanf("%d",&cashier);
	
	int arr[cashier][1000000];
	for(int i = 0;i < cashier;i ++){
		for(int j = 0;j < 1000000;j ++){
			arr[i][j] = 0;
		}
	}
	
	for(int i = 0;i < cashier;i ++){
		int tmp[1000000];
		scanf("%d", &tmp[i]);
		for (int j = 0; j < tmp[i]; j++){
			scanf("%d", &arr[i][j]);
		}
	}
	
	for(int i = 0;i < 1000000;i ++){
		for(int j = 0;j < cashier;j ++){
			if(arr[j][i] != 0){
				printf("%d ",arr[j][i]);
			}
		}
	}
}