var n,s:int64;

procedure init;
var f:text;
begin
  assign(f, 'fractii.in');
  reset(f);
  readln(f,N);
  close(f);
end;

procedure rez;
var f:text;
begin
  assign(f,'fractii.out');
  rewrite(f);
  write(f,s);
  close(f);
end;

function cmmdc(a,b:longint):longint;
begin
 if b=0 then cmmdc:=a
 else cmmdc:=cmmdc(b, a mod b);
end;

procedure calc;
var i,j:longint;
begin
 s:=2*n-1;
 for i:=2 to n do
 begin
   for j:=i+1 to n do
   if cmmdc(i,j)=1 then inc(s,2);
 end;

end;

begin
  init;
  calc;
  rez;
end.