Hey there, I am new on codeforces and I wanna train, therefore I might represent in the upcoming ACM or even ICPC. I felt like there is a gap between the B and C problems difficulty, most contests I viewed problems numbered A ,B are very easy, however problems C, D, so on are very difficult. I may think that this is the point I cannot pass , because I want to train on medium difficulty problems , what do you suggest? codeforces!