#include<fstream>
using namespace std;
#define FOR(a,b,c) for(a=b;a<c;a++)
int main()
{
	ifstream cin("ciur.in");
	ofstream cout("ciur.out");
	int n,v[30001],i,j,c1=0,sol[1001];
	cin>>n;
	FOR(i,0,30000)
		v[i]=i+2;
	FOR(i,0,30001)
		if(v[i]!=0) FOR(j,i+1,30001)
					if(v[j]%v[i]==0) v[j]=0;
	i=30000;
	while(c1!=1001&&i!=-1)
	{
		if(v[i]!=0&&v[i]<n){sol[c1]=v[i];c1++;}
		i--;
	}
	cout<<c1<<endl;
	for(i=c1-1;i>=0;i--)
		cout<<sol[i]<<" ";
	return 0;
}