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