program b4;
uses crt;
const          d    = 200;
var        taste    : char;

procedure rauf;
begin
   port(.888.):=1; delay(d);
   port(.888.):=2; delay(d);
   port(.888.):=4; delay(d);
   port(.888.):=8; delay(d);
   port(.888.):=0;
end;

procedure runter;
begin
   port(.888.):=4; delay(d);
   port(.888.):=2; delay(d);
   port(.888.):=1; delay(d);
   port(.888.):=8; delay(d);
   port(.888.):=0;
end;


begin
clrscr;
port(.888.):=0;
repeat
  taste:= readkey;
  if Taste='8'then rauf;
  if Taste='2'then runter;
until Taste=chr(27);
port(.888.):=0;
end.