public void handicap (int n)
	// set number of handicap points
	{
		int h = S < 13?3:4;
		if (n > 5)
		{
			setblack(h - 1, S / 2);
			setblack(S - h, S / 2);
		}
		if (n > 7)
		{
			setblack(S / 2, h - 1);
			setblack(S / 2, S - h);
		}
		switch (n)
		{
			case 9:
			case 7:
			case 5:
				setblack(S / 2, S / 2);
			case 8:
			case 6:
			case 4:
				setblack(S - h, S - h);
			case 3:
				setblack(h - 1, h - 1);
			case 2:
				setblack(h - 1, S - h);
			case 1:
				setblack(S - h, h - 1);
		}
		MainColor = -1;
	}