#include <cstdio>
#define pow(x) (1u<<(x&31))
#define clear(x) mask[x/32] |= pow(x)
#define isSet(x) !(mask[x/32] & pow(x))

unsigned n, nr, total, mask[1<<16], sol[1000];

int main(){
    freopen("ciur.in", "r", stdin);
    freopen("ciur.out", "w", stdout);
    scanf("%d", &n);
    for (unsigned i=2; i*i<=n; i++)
        if (isSet(i))
           for (unsigned j=i*i; j<=n; j+=i)
               clear(j);
    for (unsigned i=n; i>1; i--)
        if (isSet(i)){
           if (nr<1000) sol[nr++] = i;
           total++;
        }
    printf("%d\n", total);
    while (nr--)
          printf("%d ", sol[nr]);
}