#include<bits/stdc++.h>
using namespace std;

#define int long long

#define MAX 100

signed main(){

  int N;
  int a[MAX], used[MAX] = {}, num = 1;
  
  vector<int> ans;

  cin>>N;

  for(int i = 0; i < N; i++){
    cin>>a[i];
  }

  for(int i = 0; i < N; i++){
    if(a[i] == 2 || a[i] == -2) used[i] = true;
    if(a[i] == -2) num *= -1;
  }
  
  if(num == -1){
    bool flag = false;
    for(int i = 0; i < N; i++){
      if(a[i] == -1){
	flag = true;
	used[i] = true;
	break;
      }
    }
    
    if(flag == false){
      for(int i = N-1; i >= 0; i--){
	if(a[i] == -2){
	  used[i] = false;
	  break;
	}
      }
    }
  }
  
  for(int i = 0; i < N; i++){
    if(used[i] == true) ans.push_back(i);
  }

  cout<<ans.size()<<endl;
  
  for(int i = 0; i < ans.size(); i++){
    cout<<ans[i]+1<<endl;
  }
  
  return 0;
}


### Prompt

Develop a solution in Cpp to the problem described below:

B： 階層的計算機 (Hierarchical Calculator)

Problem

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.

Input


N
a_1 a_2 $\cdots$ a_N


Constraints

* 1 \leq N \leq 60
* -2 \leq a_i \leq 2 for i=1, ...,N (inclusive)
* Every input is given as the integer.



Output

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).

Sample Input 1


4
2 0 -2 1


Sample Output for Input 1


1
1


She evaluates the first one and gets the maximum value 2.

Sample Input 2


3
2 -2 -2


Sample Output for Input 2


3
1
2
3


She evaluates all of them and gets the maximum value 8.

Sample Input 3


2
-1 0


Sample Output for Input 3


0

She evaluates none of them and gets the maximum value 0. Empty sequence is the shorter and lexicographically smaller than any other sequences.

Sample Input 4


5
-1 2 1 -2 -1


Sample Output for Input 4


3
1
2
4


She evaluates $\langle$ 1, 2, 4 $\rangle$ ones and gets the maximum value 4. Note that $\langle$ 2, 4, 5 $\rangle$ is not lexicographically smallest one.





Example

Input

4
2 0 -2 1


Output

1
1

### Response

```cpp
#include<bits/stdc++.h>
using namespace std;

#define int long long

#define MAX 100

signed main(){

  int N;
  int a[MAX], used[MAX] = {}, num = 1;
  
  vector<int> ans;

  cin>>N;

  for(int i = 0; i < N; i++){
    cin>>a[i];
  }

  for(int i = 0; i < N; i++){
    if(a[i] == 2 || a[i] == -2) used[i] = true;
    if(a[i] == -2) num *= -1;
  }
  
  if(num == -1){
    bool flag = false;
    for(int i = 0; i < N; i++){
      if(a[i] == -1){
	flag = true;
	used[i] = true;
	break;
      }
    }
    
    if(flag == false){
      for(int i = N-1; i >= 0; i--){
	if(a[i] == -2){
	  used[i] = false;
	  break;
	}
      }
    }
  }
  
  for(int i = 0; i < N; i++){
    if(used[i] == true) ans.push_back(i);
  }

  cout<<ans.size()<<endl;
  
  for(int i = 0; i < ans.size(); i++){
    cout<<ans[i]+1<<endl;
  }
  
  return 0;
}


```