对

18171

(10-1)*88888....8 (2019个“8”) = 88…880-88…8 = 79999…9992 (2018个“9”)

= 80000…0000 – 8 (2019个“0”)

5555…555 * 8 = 444…4440 (2019个“4”)

(80000…0000 – 8 (2019个“0”)) * 5555…555 =

444…444000…000 (2019个“4”, 2020 个“0”) - 444…4440 (2019个“4”) =

444…4443555…55560 (2018个“4”, 2018个“5”) = 4*2018 + 5*2018 +3 + 6

= 18171