#include <bits/stdc++.h>
using namespace std;
bool prime[1007];
int n;
void sieve() {
  for (int i = 4; i <= 1005; i += 2) prime[i] = false, prime[i - 1] = true;
  prime[2] = true;
  for (int i = 3; i <= 1000; i += 2) {
    if (prime[i]) {
      for (int j = i * i; j <= 1005; j += i * 2) prime[j] = false;
    }
  }
}
int main() {
  ios::sync_with_stdio(false);
  sieve();
  scanf("%d", &n);
  vector<int> ans;
  for (int i = 1; i <= n; i++) {
    if (prime[i]) {
      int q = 1;
      while (q <= n / i) {
        q *= i;
        ans.push_back(q);
      }
    }
  }
  cout << (ans.size()) << endl;
  for (int i : ans) {
    printf("%d ", i);
  }
  return 0;
}
