I used 2D BIT (Range Updates, Point queries) to solve this problem . Here is my solution which results in WA. Can someone please tell me why is this solution failing?

http://www.spoj.com/problems/SELLPHN2/

I used Dinic's algorithm to solve this problem yet I am getting WA. Can someone please take a look at my code and tell me why exactly is it failing?

Link to code: https://ideone.com/T6fsQv