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