There is such a calculation formula: 18+81=99, we call two numbers like 18 and 81 reverse numbers, and how many pairs of reverse numbers equal to 88 are there.
有这样一个算式：18+81=99，我们把18和81这样的两个数叫做倒叙数，和等于88的倒序数有多少对．
<result>3</result>