#include <bits/stdc++.h>

using namespace std;

#define int long long

int n, d = 0;
int dem (int n)
{
  int d = 0;
  for (int i = 1; i <= n; ++i)
  {
    if (i % 2 == 0 and i % 3 == 0) d++;
  }
  return d;
}
void in(int n)
{
  for (int i = 1; i <= n; ++i)
  {
    if (i % 2 == 0 and i % 3 == 0) cout << i << " ";
  }
}
main() {
  //freopen(".inp", "r", stdin);
  //freopen(".out", "w", stdout);
  ios_base::sync_with_stdio(0);
  cin.tie(nullptr);
  cin >> n;
  cout << dem(n) << '\n';
  in(n);
  return 0;
}