#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, ans[1500], t, i, j, v[1100];
  memset(v, 0, sizeof(v));
  for (i = 2; i * i <= 1100; i++) {
    if (v[i] == 0) {
      for (j = i + i; j <= 1100; j += i) v[j] = 1;
    }
  }
  while (scanf("%d", &n) != EOF) {
    if (n == 1)
      printf("0\n");
    else {
      t = 0;
      for (j = 2; j <= n; j++) {
        if (v[j] == 0) {
          for (i = j; i <= n; i *= j) {
            ans[t] = i;
            t++;
          }
        }
      }
      printf("%d\n", t);
      for (i = 0; i < t - 1; i++) printf("%d ", ans[i]);
      printf("%d\n", ans[t - 1]);
    }
  }
  return 0;
}
