from collections import deque
N = int(input())
P = [0]*N
A = [[None] for _ in range(N)]
ans = deque([])
for i in range(N):
    tmp = list(map(int,input().split()))
    P[i] = tmp[0]
    A[i] = tmp[1:]

for i in range(max(P)):
    for j in range(N):
        try:
            ans.append(A[j][i]) 
        except IndexError:
            continue
print(*ans)