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: Accepted)

#include <iostream>
#include <string>
#include <cstdio>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <utility>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
using namespace std;
#define INF 1000000007
#define LINF 1000000000000000007
#define MOD 1000000007
#define int long long
#define rep(i, n) for (int i = 0; i < n; i++)
#define repb(i, n) for (int i = n - 1; i >= 0; i--)
#define MODE 1
#ifdef MODE
#define DEB(X) cout << #X << ": " << X << " ";
#define ARDEB(i, X) cout << #X << "[" << i << "]: " << X[i] << " ";
#define END cout << endl;
#else
#define DEB(X) \
    {          \
    }
#define ARDEB(i, X) \
    {               \
    }
#define END \
    {       \
    }
#endif
typedef pair<int, int> P;
struct edge{int to,cost;};

typedef long long ll;

int ans,ans2;
int n,a[211111],b[211111];



signed main(){

	cin>>n;
	rep(i,n)cin>>a[i];
	repb(i,n){
		int sum=0;
		for(int j=i*2+2;j<=n;j+=i+1)sum+=b[j-1];
		if(sum%2!=a[i])b[i]=1;
	}
	rep(i,n)if(b[i])ans++;
	cout<<ans<<endl;
	rep(i,n)if(b[i])cout<<i+1<<" ";
}