The great and very smart user Marinush had the idea of giving ranks according to gender on Codeforces. Unfortunately, his blog was 100% clickbait and didn't really talk about CF ranks, so I am going to solve this problem.
Because social norms are 100% set in stone, girls are attracted to pink and boys to blue. So, let's look at each CF rank and see if it is for women or for men:
newbie -- this is neither pink, nor blue, so it is for all genders
pupil -- this is closer to blue, so it's for males
cyan -- similar to pupil
expert -- this is clearly blue, so for males
candidate master -- this is equally blue and pink, so it's for all genders
master-- yellow is closer to pink than to blue, so it is for females
grandmaster -- red is closer to pink, so it is for females
legendary grandmaster -- black & red is closer to pink, so it is for females
So, everything master and above is female, everything expert and below is male, and, for genderless aliens like me, there is newbie and candidate master.
I hope my solution has solved this burning question on codeforces!!!
Yours unsocially,
Codepasta
Females orz