#include<fstream.h>
unsigned long n,r;
int prim(unsigned long i, unsigned long j)
{ unsigned long a,b,rr;
a=i;b=j;rr=a%b;
while(rr)
 {a=b;
  b=rr;
  rr=a%b;
 }
if(b==1)return 1;
return 0;
}
void rez(unsigned long x)
{unsigned long i,j;
i=x+1;
while(i<=n)
{r+=2;
i++;
for(j=1;j<x,i<=n;j++,i++)
 r+=2*prim(x,i);
i+=2;
}
}

int main()
{ifstream f("fractii.in");
ofstream g("fractii.out");
f>>n;
f.close();
unsigned long i;
r+=2*n-1;
if(n%2)r+=n-1;
 else r+=n-2;
for(i=3;i<n;i++)
 rez(i);
g<<r<<'\n';
g.close();
return 0;
}