Cofo PH & PC (Cofo Problem hider and problem
Download it from github.
Cofo problem hider and problem chooser : hide solved problems in codeforces problemset page !!!!! and randomly choose problems with rate that you say that you dont solved it yet !!!
use "Load Unpacked" to install it !
Install the chrome extention and once Enter your UserName and change theme between black and white
Enter two numbers then extension will choose a unsolved problem between the numbers and open it in a new tab !
Now no need to explore problemset page for a new problem just enter 2 numbers !!!!!!!!!!
And the second feature hide unsolved problem in problemset page again make the upsolving easier
Before Click :
After Click :
Have Fun & Good Luck