N = int(input())

As = []
for _ in range(N):
    PA = list(map(int, input().split()))
    P = PA.pop(0)
    if PA:
        As.append(PA)

result = []
while As:
    A = As.pop(0)
    a = A.pop(0)
    result.append(a)
    if A:
        As.append(A)

print(' '.join(str(a) for a in result))