def draw():
    screen.fill((255, 255, 255))

    for y in range(50):
        for x in range(70):
            cell_size = 5
            cell_draw_size = cell_size - 1

            screen.draw.filled_rect(
                Rect(
                    (x * cell_size, y * cell_size),
                    (cell_draw_size, cell_draw_size)
                ),
                color=(220, 220, 220)
            )