Перекраска в белый с ускорением

uses GraphAbc; const screenW = 200; screenH = 200; var a, x, y, n, s: integer; c: color; t1, t2: string; begin SetWindowSize(screenW, screenH); FloodFill(1, 1, RGB(0, 0, 0)); repeat x := 1 random(screenW); y := 1 random(screenH); c := GetPixel(x, y); if c = RGB(0, 0, 0) then begin SetPixel(x, y, RGB(255, 255, 255)); if a = 500 then sleep(0); if a < 500 then begin sleep(500 - a); a := a 5; end; n := n 1; end; until n = screenW * screenH; TextOut(70, 60, ’Done’); sleep(5000); halt(); end.