#include<fstream>
using namespace std;
#define INPUTFILE "ciur.in"
#define OUTPUTFILE "ciur.out"
#define DIM 1000001
ifstream fin (INPUTFILE);
ofstream fout (OUTPUTFILE);
int a[DIM];
int main ()
{
    long long i,j,n,k=0;
    fin>>n;
    for (i=2; i<=n; ++i)
    {
        if (!a[i])
        {
                  fout<<i<<",";
                  k++;
                  if (k%20==0)
                     fout<<endl;
                  for (j=2*i; j<=n; j+=i)
                      a[j]=1;
        }
    }
    fout<<endl;
    fout<<k;
    return 0;
}