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.
['659', 'L', 'e', '1037', '8219', 'Q', '6881', 'W', '4547', '2033', 'h', '4845', 'Q', '8053', 'Q', 'a', '5485', '9373']