program asd;

 uses Graph, crt;


var
  grDriver: Integer;
  grMode: Integer;
  ErrCode: Integer;
  XC,YC:integer;
  i,r: integer;
  f:boolean;
begin
  f:=false;
  grDriver := Detect;
  InitGraph(grDriver, grMode,'c:\bp\bgi\');
  ErrCode := GraphResult;
  if ErrCode <> grOk then
     begin
          Writeln('Graphics error:', GraphErrorMsg(ErrCode));
          halt;
     end;

  XC:=GetMaxX div 2;
  YC:=GetMaxY div 2;
  repeat
        for i:= 0 to 300 do begin
            r:= round(abs(170*cos(i*pi/100)));
        setcolor(random(16));
        ellipse(xc, yc, 0, 360,170-r, 170);
        delay(1000);
        if keypressed then begin
        f:=true;break;
        end;
        Setcolor(black);
        Ellipse (xc,yc, 0, 360,170-r, 170);

  end;
  Until f;
  CloseGraph;
end.