9-а=9-1,9-2,9-3,9-4,9-5,9-6,9-7,9-8,9-9
18-(6+с)=18-(6+1),18-(6+2),18-(6+3),18-(6+4),18-(6+5),18-(6+6),18-(6+7),18-(6+8),18-(6+9),18-(6+10),18-(6+11),18-(6+12)
(d-7)+10=(7-7)+10,(8-7)+10,(9-7)+10,(10-7)+ бесконечно
