#include <bits/stdc++.h>
using namespace std;
int res[1111];
bool sol(int d) {
  int g = 1, e;
  for (e = 2; e <= sqrt(d); e++) {
    if (d % e == 0) {
      while (d % e == 0) d /= e;
      if (d != 1) {
        g = 0;
      }
      break;
    }
  }
  return g;
}
int main() {
  int a, b, c, d, e, f, g, h;
  scanf("%d", &a);
  if (a < 2) {
    printf("0\n");
    return 0;
  }
  for (d = 2, g = 0; d <= a; d++) {
    if (sol(d)) {
      res[g++] = d;
    }
  }
  printf("%d\n", g);
  for (d = 0; d < g; d++) printf("%d%c", res[d], d != g - 1 ? ' ' : '\n');
  return 0;
}
