program sdf;
var f,g:text;
    p,q,n,nr:longint;
begin
assign(f,'fractii.in');
reset(f);
assign(g,'fractii.out');
rewrite(g);
read(f,n);
nr:=0;
  for p:=1 to n do begin
  for q:=1 to n do begin
    if (p<>q)and(q<>1)and(p<>1)then nr:=nr+1;
    if p=1 then nr:=nr+1;
    if (p=1)and(q=1) then nr:=nr+1;
  end;
  end;
write(g,nr);
close(f);close(g);
end.