#include<fstream.h>
#include<math.h>
int n,s;
ifstream f("fractii.in");
ofstream g("fractii.out");
int prim(int a,int b)
{while(a!=b)
	if(a>b) a-=b;
	else b-=a;
 if(a==1) return 1;
 else return 0;
} 
void main()
{//int p;
 f>>n;
 s=2*n-1;
 for (int i=2;i<n;i++)
	for(int j=i+1;j<=n;j++)
		if (prim(i,j)) s+=2;//(n/i*(i-1)+n%i);
 g<<s;
 g.close();
}