output_description: Output k+1 lines. First line, the length of the sequence, k. Following k
  lines, the index of the i-th element of the subsequence, s_i (one element per
  line).
input_description: N
      a_1 a_2 $\cdots$ a_N
attempt: # -*- coding: utf-8 -*-
  from collections import Counter
  
  
  def inpl():
      return tuple(map(int, input().split()))
  
  
  N = int(input())
  A = list(map(int, input().split()))
  
  C = Counter(A)
  if C[-2] % 2 == 0:
      ans = [i + 1 for i, a in enumerate(A) if abs(a) == 2]
      print(len(ans))
      if len(ans):
          print(*ans, sep="\n")
  elif C[-1] > 0:
      ans = [i + 1 for i, a in enumerate(A) if abs(a) == 2] + [A.index(-1) + 1]
      print(len(ans))
      if len(ans):
          print(*sorted(ans), sep="\n")
  else:
      del A[-A[::-1].index(-2) - 1]
      ans = [i + 1 for i, a in enumerate(A) if abs(a) == 2]
      print(len(ans))
      if len(ans):
          print(*ans, sep="\n")
  
problem_description: Ebi-chan has N formulae: y = a_i x for i =1, ..., N (inclusive). Now she
  considers a subsequence of indices with length k: s_1, s_2, ..., s_k. At
  first, let x_0 be 1 and evaluate s_1-th formulae with x = x_0. Next, let x_1
  be the output of s_1 and evaluate s_2-th formulae with x = x_1, and so on.
  
  She wants to maximize the final output of the procedure, x_{s_k}. If there are
  many candidates, she wants the """shortest one""". If there are still many
  candidates, she wants the """lexicographically smallest one""".
  
  Sequence s is lexicographically smaller than sequence t, if and only if either
  of the following conditions hold:
  
    * there exists m < |s| such that s_i = t_i for i in 1 to m (inclusive) and s_{m+1} < t_{m+1}, or
    * s_i = t_i for i in 1 to |s| (inclusive) and |s| < |t|,
  
  where |s| is the length of the s.
samples: [{"input": "4\n    2 0 -2 1", "output": "for Input 1\n\n    \n    \n    1\n    1\n    \n\nShe evaluates the first one and gets the maximum value 2."}, {"input": "3\n    2 -2 -2", "output": "for Input 2\n\n    \n    \n    3\n    1\n    2\n    3\n    \n\nShe evaluates all of them and gets the maximum value 8."}, {"input": "2\n    -1 0", "output": "for Input 3\n\n    \n    \n    0\n\nShe evaluates none of them and gets the maximum value 0. Empty sequence is the\nshorter and lexicographically smaller than any other sequences."}, {"input": "5\n    -1 2 1 -2 -1", "output": "for Input 4\n\n    \n    \n    3\n    1\n    2\n    4\n    \n\nShe evaluates $\\langle$ 1, 2, 4 $\\rangle$ ones and gets the maximum value 4.\nNote that $\\langle$ 2, 4, 5 $\\rangle$ is not lexicographically smallest one."}]