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 <algorithm>
#include <cmath>
#include <deque>
#include <iomanip>
#include <iostream>
#include <limits.h>
#include <map>
#include <numeric>
#include <queue>
#include <sstream>
#include <string>
#include <string.h>
#include <tuple>
#include <vector>

#define REP(i,x) for(int i{ 0 }; i < (int)(x); i++)
#define REPC(i,x) for(int i{ 0 }; i <= (int)(x); i++)
#define RREP(i,x) for(int i{ (int)(x) - 1 }; i >= 0 ;i--)
#define RREPC(i,x) for(int i{ (int)(x)}; i >= 0; i--)
#define REP1O(i,x) for(int i{ 1 }; i < (int)(x); i++)
#define REP1C(i,x) for(int i{ 1 }; i <= (int)(x); i++)
#define REPIT(i,x) for(auto i{(x).begin()}; i != (x).end(); i++) 

#define PB push_back
#define MP make_pair
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()

using namespace std;

typedef int64_t ll;
typedef double dbl;
typedef vector<bool> Vb;
typedef vector<char> Vc;
typedef vector<double> Vd;
typedef vector<int> Vi;
typedef vector<ll> Vl;
typedef vector<string> Vs;
typedef vector<vector<int>> VVi;
typedef vector<vector<ll>> VVl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;

template<class T> inline bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
inline void swap(ll& a, ll& b) { a ^= b; b ^= a; a ^= b; }
inline void swap(int& a, int& b) { a ^= b; b ^= a; a ^= b; }
inline void YES() { cout << "YES" << endl; } inline void Yes() { cout << "Yes" << endl; }
inline void NO() { cout << "NO" << endl; } inline void No() { cout << "No" << endl; }

const int inf = 1 << 30;
const ll linf = 1LL << 60;
const int MOD = 1000000007;

int n;
Vi va, ans, vput;

void init()
{
	cin >> n;
	va.resize(n + 1, 0);
	vput.resize(n + 1, 0);
	REP1C(i, n)
		cin >> va[i];
}

int main()
{
	init();

	for (int i = n; i > 0; --i)
	{
		int cnt = 0;
		for (int j = i * 2; j <= n; j += i)
			cnt ^= vput[j];

		if (va[i] != cnt)
		{
			ans.PB(i);
			vput[i] = 1;
		}
	}

	cout << SZ(ans) << endl;
	REP(i, SZ(ans))
		cout << ans[i] << " ";
	cout << endl;
}