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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;

class Main {
	public static void main(String args[]) throws IOException {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		Solver solver = new Solver();
		solver.init();
		solver.readHead(in.readLine());
		solver.readA(in.readLine());
		// for (; solver.hasNext();) {
		// solver.readBody(in.readLine());
		// }
		// solver.solve();
	}
}

class Solver {
	int N;
	int cnt;

	public void init() {
		N = 0;
		cnt = 0;
	}

	public void readHead(String str) {
		String[] strArr = str.split("\\s+");
		N = Integer.parseInt(strArr[0]);
		// System.out.println(N);
	}

	public void readA(String str) {
		String[] strArr = str.split("\\s+");
		int[] A = new int[N + 1];
		for (int i = 1; i <= N; i++)
			A[i] = Integer.parseInt(strArr[i - 1]);
		HashSet<Integer> B = new HashSet<Integer>();
		for (int i = N; i >= 1; i--) {
			int b = A[i];
			for (int j = i * 2; j <= N; j = j + i) {
				if (B.contains(j)) {
					if (b == 0)
						b = 1;
					else
						b = 0;
				}
			}
			if (b == 1)
				B.add(i);
		}
		System.out.println(B.size());
		String sep = "";
		for (int n : B) {
			System.out.print(sep);
			if ("".equals(sep))
				sep = " ";
			System.out.print(n);
		}
		System.out.println();
	}

	public boolean hasNext() {
		return cnt < N;
	}

	public void readBody(String str) {
		// System.out.println(str);
		cnt++;
	}

	public void solve() {
	}
}