#pragma option -3 -a -Z -O2 -r
#include<fstream.h>
unsigned long n;
int nrprime(unsigned long x,unsigned long y)
{unsigned long r;
 do
  {r=x%y;
   x=y;
   y=r;
  }
 while(r);
 if(x==1) return 1;
   else return 0;
}
int main()
{unsigned long i,j,c=0;
 ifstream f("fractii.in");
 ofstream g("fractii.out");
 f>>n;
 //cout<<"n="; cin>>n;
 f.close();
 c=2*n-1;
 for(i=2;i<=n;i++)
  {if(i%2==0) for(j=3;j<=n;j=j+2) if(nrprime(i,j)) c++;
   else for(j=2;j<=n;j++)
	   if(nrprime(i,j)) c++;
  }
 //cout<<c<<'\n';
 g<<c<<'\n';
 g.close();
return 0;
}