Today, I studied the video lectures related to data Structures for nptal video 1-7 and managed all the data in my system that I want to be save as I was going to upgrade my system. Initially, I tried to upgrade 14 to 16 but that wouldn’t happen as due to my fault I update my systems ppa to that of ubuntu 15 and know core of system was ubuntu 15 and rest ubuntu 14 plus update manager was also not working.