#include<stdio.h>

int main()
{
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);

	long long unsigned n,i,j,contor=1,a,b,r;
	scanf("%llu",&n);

	for(i=1;i<n;++i)
		for(j=i+1;j<=n;++j)
		{
			a=i;
			b=j;
			do
			{
				r=a%b;
				a=b;
				b=r;
			}
			while(r);
			if(a==1)
				contor+=2;
		}

	printf("%llu",contor);

	return 0;
}