是否存在 aaa , bbb , ccc 满足 ab≥ca^b\ge cab≥c 且 b≥φ(c)b\ge \varphi(c)b≥φ(c) 且 abmodφ(c)+φ(c)<ca^{b mod \varphi(c)+\varphi(c)}<cabmodφ(c)+φ(c)<c
