#include <iostream>
#include <fstream>
#include <sstream>

#include <vector>
#include <set>
#include <bitset>
#include <map>
#include <deque>
#include <string>

#include <algorithm>
#include <numeric>

#include <cstdio>
#include <cassert>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <cmath>

#define pb push_back
#define pbk pop_back
#define mp make_pair
#define fs first
#define sc second
#define all(x) (x).begin(), (x).end()
#define foreach(i, a) for (__typeof((a).begin()) i = (a).begin(); i != (a).end(); ++i)
#define len(a) ((int) (a).size())

#ifdef CUTEBMAING
#define eprintf(...) fprintf(stderr, __VA_ARGS__)
#else
#define eprintf(...) 42
#endif

using namespace std;

typedef long long int64;
typedef long double ld;
typedef unsigned long long lint;

const int inf = (1 << 30) - 1;
const int64 linf = (1ll << 62) - 1;

int main() {
    int n; cin >> n;
    vector<int> is_prime(n + 1, true), primes;
    is_prime[0] = is_prime[1] = 0;
    for (int i = 2; i * i <= n; i++) {
        if (is_prime[i]) {
            for (int j = i * i; j <= n; j += i) {
                is_prime[j] = false;
            }
        }
    }
    vector<int> ans;
    for (int i = 1; i <= n; i++) {
        if (is_prime[i]) {
            int q = 1;
            while (q <= n / i) {
                q *= i;
                ans.push_back(q);
            }
        }
    }
    cout << len(ans) << endl;
    for (int i : ans) {
        printf("%d ", i);
    }
    puts("");
    return 0;
}