var n,a,i,j,b,nr,r :longint;
f,g:text;
begin
assign(f,'fractii.in');reset(f);
assign(g,'fractii.out');rewrite(g);
read(f,n);
for i:=2 to n do
   for j := 2 to n do
   begin
    if i<>j then
      begin
        a:=i;b:=j;
        repeat
         r:=a mod b;
         a:=b;
         b:=r;
        until r = 0;
      end;
      if a=1 then
        nr:=nr+1;
      a:=0;b:=0;
      end;
      nr:=nr+2*n-1;
write(g,nr);
close(f);close(g);
end.