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.
['V', 'L', 'Z', '2651', '7071', '2277', 'T', '8911', '3019', 'q', '1419', '1351', 'L', '1107', 'r', 'P', '4895', '3431', '1613']