N = int(input())

G = [[] for _ in range(N + 2)]
A, B = [0], [0]
stack = []
for i in range(1, N + 1):
  a, b = map(int, input().split())
  A.append(a)
  B.append(b)
  if a == 1:
    G[i + 1].append(i)
    if b == 1:
      j = stack.pop()
      G[i].append(j)
  elif b == 1:
    print(i)
    j = stack.pop()
    print(j)
    while len(G[j]):
      j = G[j].pop()
      print(j)
  elif b == 2:
    stack.append(i)
  else:
    print(i)
    j = i
    while len(G[j]):
      j = G[j].pop()
      print(j)