#include<iostream.h>
#include<stdio.h>
int main()
{ long long p, n, c=0, q, r, cp, cq;
  freopen("fractii.in", "rt", stdin);
  freopen("fractii.out", "wt", stdout);
  cin>>n;
  for(p=2;p<=n/2;p++)
  c+=(n/p-1)*2+1;
  for(p=n/2+1;p<=n;p++)
   for(q=p+1;q<=n;q++)
   {cp=p; cq=q;
    while(r=cp%cq)
     { cp=cq;
       cq=r;
     }
    if(cq!=1) c+=2;
   }
  cout<<n*n-c-(n+1)/2<<endl;
  return 0;
}