#include <stdio.h>

FILE *f;
long int n,nrf=0,i,j;

int main()
{
	f=fopen("fractii.in","r");
   fscanf(f,"%ld",&n);
   fclose(f);

   if(n>=1)
   {
   	nrf+=n;
	}
   for(i=2;i<=n;i++)
   {
   	for(j=1;j<=i;j++)
      {
      	if(i%j==0){nrf++;}
      }
   }

   f=fopen("fractii.out","w");
   fprintf(f,"%ld",nrf);
   fclose(f);
	return 0;
}