package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

	var ans []int
	primes := make([]bool, n+1)
	for i := 2; i <= n; i++ {
		primes[i] = true
	}

	for i := 2; i <= n; i++ {
		if primes[i] {
			for j := i * i; j <= n; j += i {
				primes[j] = false
			}
			for q := i; q <= n; q *= i {
				ans = append(ans, q)
			}
		}
	}

	fmt.Println(len(ans))
	for i, v := range ans {
		if i > 0 {
			fmt.Print(" ")
		}
		fmt.Print(v)
	}
	fmt.Println()
}