Hi , I am a beginner programmer and i need some help . Basically i was working on a problem on codeforces (using java) and i am getting Null Pointer Excpetion. I am not able to understand the root cause of this problem and how to sort it out..

I tried searching on Internet , and i got a few answers about my problem but after even implementing them , my code is giving the same exception .. Can anyone tell me what is the solution for this problem.. Thanks .. !!

Codelink-> http://pastebin.com/qCxiyeH4