#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T &&t, V &&...v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
const int MAXN = 1e3 + 100;
bool p[MAXN];
int n;
void sieve(int x) {
  for (int i = 2; i * i <= x; i++) {
    if (p[i]) {
      for (int j = i + i; j <= x; j += i) p[j] = 0;
    }
  }
}
int main() {
  memset(p, 1, sizeof(p));
  sieve(MAXN - 10);
  cin >> n;
  vector<int> ans;
  for (int i = 2; i <= n; i++) {
    if (p[i]) {
      ans.push_back(i);
      int ii = i * i;
      while (ii <= n) {
        ans.push_back(ii);
        ii *= i;
      }
    }
  }
  cout << ans.size() << endl;
  for (int i = 0; i < (int)(ans.size()); i++) {
    cout << ans[i] << " ";
  }
  return 0;
}
