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