Problem:
Score : 400 points

Problem Statement

There are N empty boxes arranged in a row from left to right.
The integer i is written on the i-th box from the left (1 \leq i \leq N).

For each of these boxes, Snuke can choose either to put a ball in it or to put nothing in it.

We say a set of choices to put a ball or not in the boxes is good when the following condition is satisfied:

For every integer i between 1 and N (inclusive), the total number of balls contained in the boxes with multiples of i written on them is congruent to a_i modulo 2.

Does there exist a good set of choices? If the answer is yes, find one good set of choices.

Constraints

All values in input are integers.

1 \leq N \leq 2 \times 10^5

a_i is 0 or 1.

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

If a good set of choices does not exist, print -1.

If a good set of choices exists, print one such set of choices in the following format:

M
b_1 b_2 ... b_M

where M denotes the number of boxes that will contain a ball, and b_1,\ b_2,\ ...,\ b_M are the integers written on these boxes, in any order.

Sample Input 1

3
1 0 0

Sample Output 1

1
1

Consider putting a ball only in the box with 1 written on it.

There are three boxes with multiples of 1 written on them: the boxes with 1, 2, and 3. The total number of balls contained in these boxes is 1.

There is only one box with a multiple of 2 written on it: the box with 2. The total number of balls contained in these boxes is 0.

There is only one box with a multiple of 3 written on it: the box with 3. The total number of balls contained in these boxes is 0.

Thus, the condition is satisfied, so this set of choices is good.

Sample Input 2

5
0 0 0 0 0

Sample Output 2

0

Putting nothing in the boxes can be a good set of choices.

Solution in C++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
	vector <int> a,ans;
	int co[50000]={};
	int n,t;
	bool l=false;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>t;
		a.push_back(t);
	}
	for(int i=n-1;i>=0;i--){
		int num=0;
		for(int j=i;j<n;j+=i+1){
			if(co[j]==1){
				num++;
			}
		}
		if(num%2!=a[i]){
			co[i]=1;
			ans.push_back(i+1);
		}
	}
	cout<<ans.size()<<endl;
	if(ans.size()==0){
		cout<<-1<<endl;
	}else{
		for(int i=0;i<ans.size();i++){
			cout<<ans[i];
			if(i==ans.size()-1){
				cout<<endl;
			}else{
				cout<<' '<<endl;
			}
		}
	}
	return 0;
}