#include<fstream>
using namespace std;
ifstream in("ciur.in");
ofstream out("ciur.out");
int main()
{	long i,j,n,v[100000],nr=0;
	in>>n;
	for (i=1;i<=n;i++)
		v[i]=i;
	v[1]=0;
	for (i=2;i<=n/2;i++)
	{j=2;
		while (i*j<=n)
		{v[i*j]=0;
		 j++;
		}
	}
	for (i=2;i<=n;i++)
		if (v[i]) nr++;
	out<<nr<<endl;
	for (i=2;i<=n;i++)
		if (v[i]) out<<v[i]<<" ";
	

	return 0;
}