n=int(input())
lst=[[0]*1001 for _ in range(1001)]
max_a=0
for i in range(n):
    a,*b=map(int,input().split())
    for j in range(a):
        # print(i,j)
        lst[i][j]=b[j]
    max_a=max(max_a,a)
# print(lst,max_a)
ans_lst=[]
for i in range(1001):
    for j in range(1001):
        ans_lst.append(lst[j][i] if lst[j][i]!=0 else None)
print(*[i for i in ans_lst if i!=None])