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.util.*;

public class Main {
	public static void printArray(int[] a) {
		for (int i = 0; i < a.length; i++) {
			System.out.print(a[i] + ", ");
		}
		System.out.println();
	}

	// public static<T> void printArrayT(T[] a) {
	// 	for (int i = 0; i < a.length; i++) {
	// 		System.out.print(a[i] + ", ");
	// 	}
	// 	System.out.println();
	// }

	// public static class Triple implements Comparable<Triple> {
	// 	public int A, B, C;
	// 	Triple(int A, int B, int C) {
	// 		this.A = A;
	// 		this.B = B;
	// 		this.C = C;
	// 	}

	// 	@Override
	// 	public String toString() {
	// 		return String.format("(%d, %d, %d)", A, B, C);
	// 	}

	// 	@Override
	// 	public int compareTo(Triple o) {
	// 		int a = this.A - o.A;
	// 		if (a != 0) return a;
	// 		int b = this.B - o.B;
	// 		if (b != 0) return b;
	// 		return this.C - o.C;
	// 	}
	// }

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] A = new int[N + 1];
		for (int i = 1; i <= N; i++) {
			A[i] = sc.nextInt();
		}
		// printArray(A);
		int[] sum = new int[N+1];
		for (int i = N; i > 0; i--) {
			// if (i * 2 > N) {
			// 	sum[i] = A[i];
			// 	continue;
			// }
			int sum2 = A[i];
			for (int j = i * 2; j <= N; j += i) {
				sum2 += sum[j];
			}
			sum[i] = sum2 % 2;
		}
		// printArray(sum);

		int cnt = 0;
		boolean isFirst = true;
		StringBuilder sb = new StringBuilder();
		for (int i = 1; i <= N; i++) {
			if (sum[i] != 0) {
				cnt++;
				if (isFirst) {
					isFirst = false;
				} else {
					sb.append(" ");
				}
				sb.append(i);
			}
		}

		System.out.println(cnt);
		System.out.println(sb.toString());
	}
}