In this task, you are given an input list A. You need to find all the elements of the list that are numbers and calculate their sum.
['f', 'h', '8035', '2377', '1629', 'a', '765', '7199', '2177', 'l', '5681', 't', '7037', 'D', 'W', '4717', '6083', 'u', 'G', '2147']