How to filter problem in codeforces?

Hello all,
I have read many blogs and have heard more than a dozen time from very good competitive programmers that to practice CP from Codeforces is to sort the problems of codeforces rounds : like do A level ~100 problems then B then C… plus Division wise.
So i want to ask how to filter the problems in this manner, I am able to sort the problems submission wise but not in this way, please can anybody tell me how to do this, i will be very thankful.

For filtering the problems in this manner, u should refer a2oj Ladder.


Or you can solve this sheet by Prof. Mostafa Saad. Follow this link:

It has reasonable no of problems for difficulty levels on Codeforces, so you can practice them on daily basis for 3-4 months and that time is enough to finish this sheet.