N = int(input().strip())
P = []
for i in range(N):
  PA = [i for i in input().strip().split(' ')]
  A = PA[1:]
  P.append(A)

cnt = -1
ans = []

while cnt != 0:
  cnt = 0
  for i in range(N):
    if len(P[i]) > 0:
      ans.append(P[i].pop(0))
      cnt += 1

ans = ' '.join(ans)
print(ans)