-4 0 1 4 0 1 0 -3 1 0 3 1 8 -3 1 -6 -3 1 1 0 -4 0 1 0 -4 0 -9 1 0 4 0 1 0 4 0 -9 0 1 3 A B C F a A C b B C l F C D C a b E C b l