#include <cstdio>
int k=0;
int divide(int x,int y)
{
	if(x==y)
		return 1;
	else if(x>y)
		divide(y,x);
	else
	{
		int i;
		for(i=2;i<=y;i++)
			if(x%i==0 && y%i==0)
				return 1;
		return 0;
	}
}
int main()
{
	long n;
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);
	scanf("%d",&n);
	int i,j;
	unsigned long r=n*n;
	for(i=2;i<=n;i++)
	{
		k=0;
		for(j=2;j<=i;j++)
			if(divide(j,i))
				k++;
		if(k!=1)
			r-=2*k-1;
		else r--;
	}
	printf("%lld\n",r);
}