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.
['8353', 'f', '1799', '6985', '2975', 'J', '9105', 'f', 'v', 'C', 'V', '9327', '3015', 'e', 'h', '439', '4969', 'c']