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.
['D', '3423', '3183', 'u', 'W', '5929', '8727', 'W', '3741', 'h', 'V', 's', '3261', '3905', 'c', 'A', '2103', '1119']