C554 Multiple Filtering Methods

"Farr is right. Qin Luo should be using the second sieve method." Professor Henrick joined the discussion. "I won't hide it from you. Actually, I have some knowledge about the sieve method. I have also tried to deduce the second sieve method multiple times. However, due to special reasons, the deduction was unsuccessful. "

"However, someone has proved it for me now