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# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace Main
{
    public static class Program
    {
        static void Main(string[] arg)
        {
            int n = int.Parse(Console.ReadLine());
            var array = GetIntList(Console.ReadLine());
            int num = 0;
            var list = new List<int>();

            for(int i = 1; i<n;i++){
                int amount = array.TakeWhile(x => x%i == 0).Sum();
                if(amount%2 != 0){
                    num++;
                    list.Add(i);
                }
            }
            Console.WriteLine(num);
            foreach(int a in list){
                Console.Write(a + " ");
            }

            //Console.WriteLine(answer);
            Console.ReadLine();
 
        }
        
        #region libraries
        private static int[] GetIntList(string line)
        {
            return line.Split(' ').Select(x => int.Parse(x)).ToArray();
 
        }
        private static double[] GetDoubleList(string line)
        {
            return line.Split(' ').Select(x => double.Parse(x)).ToArray();
 
        }
        private static ulong[] GetUlongList(string line)
        {
            return line.Split(' ').Select(x => ulong.Parse(x)).ToArray();
        }
        private static long[] GetLongList(string line)
        {
            return line.Split(' ').Select(x => long.Parse(x)).ToArray();
        }
        private static int SearchNearest(this IEnumerable<int> list, int target)
        {
            var min = list.Min(c => Math.Abs(c - target));
            return list.First(c => Math.Abs(c - target) == min);
        }
        public static bool IsOdd(int i)
        {
            return i % 2 == 1 ? true : false;
        }
        public static int Gcd(int a,int b)
        {
            if(a < b)
            {
                Gcd(b, a);
            }
            while (b != 0)
            {
                var rm = a % b;
                a = b;
                b = rm;
            }
            return a;
        }
        #endregion
    }
}