CPM national leader Prakash Karat said Polavaram dam design should be changed so that it will benefit both Telangana and Andhra Pradesh states. Speaking at a press meet in Vijayawada, Prakash also said, Telangana and AP government should sort out differences and work for the progress of both the states. Use Blackmoney is the factor, we lost in the recent elections. The Left parties will bounce back in future and show our stamina whenever needed.