The fractional unit is (1/5), the smallest false fraction is ((())/(())), and the largest true fraction is ((())/(())). How many such fractional units are there in these two fractions?
分数单位是(1/5)的最小假分数是((())/(()))，最大真分数是((())/(()))．这两个分数里一共有多少个这样的分数单位．
<result>9</result>