Can' assign table elements to variables

I know you are trying your best to help me but looks like i don't know how to explain the end goal of this so i will send you table which i want as a result and yu tell me if it's possible to do it. We compare each 2 tasks, for example task 1 with task 2 and nothing changes etween them because their id's are different, task 1 with task 2, same id's and we can see that task 1 end date is same as task 2 start date so we need to move task 2 start date by task 1 end date + 1 and also move task 2 end date too. And we do that for task 2 with task 3 etc.