program fractii;
var nr,p,k,n,a,b:longint;
    f:text;
begin
Assign(f,'fractii.in');reset(f);
read(f,n);close(f);
nr:=1+2*(n-1);
for p:=2 to n do
  for k:=2 to p-1 do begin
    a:=p;b:=k;
    While a*b<>0 do
      if a>b then a:=a mod b
             else b:=b mod a;
      if a+b=1 then nr:=nr+2;
                     End;
Assign(f,'fractii.out');rewrite(f);
Write(f,nr);close(f);
End.