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