一个GWD数学。。。我脑子短路了。。。犇犇来help~~~

piaoface

条件1. prime number is a dividor of n, ex. prime number 3, if n=18, 18/3=6. also, 3^2 is a dividor of 18, 18/9=2. but 18 is not a square of an integer.
条件2. alone is fine.

-- by 会员 dian89 (2011/11/23 11:20:37)

所以结果也是D么。。