Hello everyone! After endless debugging, I finally got AC on all the samples and submitted my code of F — Bear and Chemistry. However, it got Wrong Answer on test #67(which is not a hack, but a big case with n=300000,m=300000,q=100000!), and there are 77 testcases in all(which means I have passed a major part of them)!

I am pretty exhausted now. I wonder if any one of you experienced programmers can share with your approach in tackling this kind of thing. I would be most grateful!