11111 * ( 5 * 9) 11111 * ( 7 * 4)
------------------------------------------------------ : --------------------------------------------- =
(1+9) + (3+7) + (8+2) + (6+4) + 5 (3+7) + (6 + 4) + (1 + 2) + 5
11111 * 45 28
---------------------- × ----------------------- = 1
45 11111 * 28