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 PyPy3 (2.4.0) (judge verdict: Accepted)

def divisors(n: int)->list:
    for i in range(1, int(n**0.5)+1):
        if n % i == 0:
            yield i
            if i != n // i:
                yield n // i


def preparing_boxes(N: int, A: list)->list:
    B = []
    # C = [0] * N

    for i in range(N, 0, -1):
        # print('=== {} ==='.format(i))
        a = A[i-1]
        if a == 0:
            continue
        B.append(i)
        # C[i-1] = 1

        for div in divisors(i):
            # print(div)
            A[div-1] = 1 - A[div-1]

    # print(''.join(str(i) for i in C))

    return B


if __name__ == "__main__":
    N = int(input())
    A = list(map(int, input().split()))
    ans = preparing_boxes(N, A)
    print(len(ans))
    print(' '.join(str(i) for i in ans))