n = int(input())
a = []
for _ in range(n):
    a_i = list(map(int, input().split()))
    a.append(a_i[1:])

len_max = 0
for i in range(n):
    if len_max < len(a[i]):
        len_max = len(a[i])

ans = []
for _ in range(len_max):
    for i in range(n):
        if len(a[i]) != 0:
            ans.append(a[i].pop(0))

print(*ans)