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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

func dummy() {
	math.Abs(1.0)
}

/************I/O***********/

var (
	// ReadString returns a WORD string.
	readString func() string
	stdout     *bufio.Writer
)

func init() {
	readString = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func readIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = readInt()
	}
	return b
}

// ReadFloat64 returns an float64.
func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func readFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = readFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func readRuneSlice() []rune {
	return []rune(readString())
}

/*********math********/
func mod(val int, m int) int {
	res := val % m
	if res < 0 {
		res += m
	}
	return res
}

func absInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}
func minInt(val ...int) int {
	res := val[0]
	for i := 1; i < len(val); i++ {
		if res > val[i] {
			res = val[i]
		}
	}
	return res
}
func maxInt(val ...int) int {
	res := val[0]
	for i := 1; i < len(val); i++ {
		if res < val[i] {
			res = val[i]
		}
	}
	return res
}

const MOD = 1000000007

func c(a int, b int) int {
	if a < 0 || b < 0 {
		return 0
	}

	res := 1
	for i := 0; i < b; i++ {
		res *= a - i
	}
	for i := 0; i < b; i++ {
		res = res / (i + 1)
	}
	return res
}

func main() {

	N := readInt()
	a := make([]int, N+1)
	a[0] = 0
	for i := 0; i < N; i++ {
		a[i+1] = readInt()
	}

	ans := make([]int, N)
	l := 0

	for i := N; i > 0; i-- {
		t := 0
		for j := 1; j <= N/i; j++ {
			if a[j*i] == 1 {
				t = 1 - t
			}
		}
		if t == 1 {
			ans[l] = i
			a[i] = 1
			l++
		} else {
			a[i] = 0
		}

	}
	fmt.Println(l)
	for i := 0; i < l; i++ {
		fmt.Println(ans[i])
	}

}