# include <fstream>



fstream f("fractii.in",ios::in);
fstream t("fractii.out",ios::out);


long i,j,n,fr;
int c,k,b,l;

int main ()
{
f>>n;
for (i=1;i<=n;i++)
		 for (j=1;j<=n;j++)
				  {
				  if(j==1)
					 k++;
				  if (i%j!=0&&j!=1)
					    k++;
				  }
t<<k-1;
return 0;
}