public static String getLeadNucletide(int row) {
		switch (row) {
		case 0: 
		case 4: return "A";
		case 1: 
		case 5: return "C";
		case 2:
		case 6: return "G";
		case 3:
		case 7: return "U";
		}
		return null;
	}