#include <bits/stdc++.h>
using namespace std;
const long long int Maxn3 = 1e3 + 10;
const long long int Maxn4 = 1e4 + 10;
const long long int Maxn5 = 1e5 + 10;
const long long int Maxn6 = 1e6 + 10;
const long long int Maxn7 = 1e7 + 10;
const long long int Maxn8 = 1e8 + 10;
const long long int Maxn9 = 1e9 + 10;
const long long int Maxn18 = 1e18 + 10;
const long long int Mod1 = 1e7 + 7;
const long long int Mod2 = 1e9 + 7;
const long long int LLMax = LLONG_MAX;
const long long int LLMin = LLONG_MIN;
const long long int INTMax = INT_MAX;
const long long int INTMin = INT_MIN;
long long int mn = LLMax, mx = LLMin;
vector<long long int> ask;
bool mark[Maxn3];
int main() {
  ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
  long long int n;
  cin >> n;
  for (long long int i = 2; i <= n; i++) {
    if (!mark[i]) {
      for (long long int j = i; j <= n; j *= i) ask.push_back(j);
      for (long long int j = i << 1; j <= n; j += i) mark[j] = 1;
    }
  }
  cout << ask.size() << '\n';
  for (long long int i = 0; i < ask.size(); i++) cout << ask[i] << ' ';
  return 0;
}
