#include<stdio.h>
FILE *in=fopen("fractii.in","r");
FILE *out=fopen("ffractii.out","w");
long int n,i,j,nr;
int main()
{
fscanf(in,"%ld",&n);
for(i=1;i<=n;i++) for(j=i;j<=n;j++) if(j%i!=0) nr++;
fprintf(out,"%ld",nr);
return 0;
}