#include<stdio.h>

int main()
{
	FILE *f=fopen("fractii.in","r");
	int n,nr[1000001],i,j,total=0;

	fscanf(f,"%i",&n);
	fclose(f);

	nr[1]=0;
	for(i=2;i<=n;i++)
		nr[i]=1;
	for(i=2;i<=n;i++)
		for(j=i+i;j<=n;j+=i)
		{
			nr[j]++;
			nr[i]++;
		}
	for(i=1;i<=n;i++)
		total+=n-nr[i];
	f=fopen("fractii.out","w");
	fprintf(f,"%i\n",total);
	fclose(f);
	return 0;
}