#include <bits/stdc++.h>

using namespace std;

#define INF 1001000100010001000
#define MOD 1000000007
#define EPS 1e-10
#define int long long
#define rep(i, N) for (int i = 0; i < N; i++)
#define Rep(i, N) for (int i = 1; i < N; i++)
#define For(i, a, b) for (int i = (a); i < (b); i++)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define i_i pair<int, int>
#define vi vector<int>
#define vvi vector<vi >
#define vb vector<bool>
#define vvb vector<vb >
#define vp vector< i_i >
#define all(a) (a).begin(), (a).end()
#define Int(x) int x; cin >> x;
#define int2(x, y) Int(x); Int(y);
#define int3(x, y, z) Int(x); int2(y, z);
#define fir first
#define sec second
#define ffir first.first
#define fsec first.second
#define sfir second.first
#define ssec second.second
#define Decimal fixed << setprecision(10)

//int dxy[5] = {0, 1, 0, -1, 0};
// // assign avl ncm dijkstra geo2 kruskal graph uf lca BIT
// matrix dinic next_combination topcoder lcm vi st gin
// cusum segtree

signed main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    Int(n);
    vector<int> data(n);
    for (int i = 0; i < n; i++) {
        cin >> data[i];
    }
    
    vb used(n, false);
    rep(i, n) {
        if (data[i] == 2) {
            used[i] = true;
        }
    }

    int cnt = 0;
    vi yui(2, 0);
    rep(i, n) {
        if (data[i] == -1) {
            yui[0]++;
        } else if (data[i] == -2) {
            yui[1]++;
        }
    }

    if ((yui[0] + yui[1]) % 2 == 0) {
        cnt = 0;
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
        if (cnt % 2) {
            rep(i, n) {
                if (data[i] == -1) {
                    used[i] = true;
                    break;
                }
            }
        }
    } else if (yui[1] % 2 == 0) {
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
    } else if (yui[0] && yui[1]) {
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
        if (cnt % 2) {
            rep(i, n) {
                if (data[i] == -1) {
                    used[i] = true;
                    break;
                }
            }
        }
    } else if (yui[1]) {
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
        for (int i = n-1; i >= 0; i--) {
            if (data[i] == -2) {
                used[i] = false;
                break;
            }
        }
    }

    cnt = 0;
    rep(i, n) cnt += used[i];

    cout << cnt << endl;
    rep(i, n) {
        if (used[i]) {
            cout << i+1 << endl;
        }
    }

    return 0;
}


### Prompt

Generate a Cpp solution to the following problem:

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 INF 1001000100010001000
#define MOD 1000000007
#define EPS 1e-10
#define int long long
#define rep(i, N) for (int i = 0; i < N; i++)
#define Rep(i, N) for (int i = 1; i < N; i++)
#define For(i, a, b) for (int i = (a); i < (b); i++)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define i_i pair<int, int>
#define vi vector<int>
#define vvi vector<vi >
#define vb vector<bool>
#define vvb vector<vb >
#define vp vector< i_i >
#define all(a) (a).begin(), (a).end()
#define Int(x) int x; cin >> x;
#define int2(x, y) Int(x); Int(y);
#define int3(x, y, z) Int(x); int2(y, z);
#define fir first
#define sec second
#define ffir first.first
#define fsec first.second
#define sfir second.first
#define ssec second.second
#define Decimal fixed << setprecision(10)

//int dxy[5] = {0, 1, 0, -1, 0};
// // assign avl ncm dijkstra geo2 kruskal graph uf lca BIT
// matrix dinic next_combination topcoder lcm vi st gin
// cusum segtree

signed main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    Int(n);
    vector<int> data(n);
    for (int i = 0; i < n; i++) {
        cin >> data[i];
    }
    
    vb used(n, false);
    rep(i, n) {
        if (data[i] == 2) {
            used[i] = true;
        }
    }

    int cnt = 0;
    vi yui(2, 0);
    rep(i, n) {
        if (data[i] == -1) {
            yui[0]++;
        } else if (data[i] == -2) {
            yui[1]++;
        }
    }

    if ((yui[0] + yui[1]) % 2 == 0) {
        cnt = 0;
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
        if (cnt % 2) {
            rep(i, n) {
                if (data[i] == -1) {
                    used[i] = true;
                    break;
                }
            }
        }
    } else if (yui[1] % 2 == 0) {
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
    } else if (yui[0] && yui[1]) {
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
        if (cnt % 2) {
            rep(i, n) {
                if (data[i] == -1) {
                    used[i] = true;
                    break;
                }
            }
        }
    } else if (yui[1]) {
        rep(i, n) {
            if (data[i] == -2) {
                cnt++;
                used[i] = true;
            }
        }
        for (int i = n-1; i >= 0; i--) {
            if (data[i] == -2) {
                used[i] = false;
                break;
            }
        }
    }

    cnt = 0;
    rep(i, n) cnt += used[i];

    cout << cnt << endl;
    rep(i, n) {
        if (used[i]) {
            cout << i+1 << endl;
        }
    }

    return 0;
}


```