For last 6-8 month I am doing problem solve in Codeforce. But still I can't solve B problem in contest smoothly.I saw many problem solver who started coding with me and now they can solve C problem even D problem easily.They can think problem easily but that problem i need to think with long time even 1 or 2 week.I feel frustrated when i see them.Now my ques is,what should I do for improve?I want to be a very good problem solver.I know it's all about solve more and more problem.With solving problem,do i need to do anything?