#include<stdio.h>
int main()
{
long a,b,i,n,r,nr=0,j;
freopen("fractii.in","r",stdin);
freopen("fractii.out","w",stdout);
scanf("%ld",&n);
for(i=1;i<n;i++)
	{
	a=i;
	for(j=i+1;j<=n;j++)
		{
		a=i;
		b=j;
		while(b!=0)
			{
			r=a%b;
			a=b;
			b=r;
			}
		if(a==1)
			nr++;
		}
	}
printf("%ld",nr*2+1);
return 0;
}