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.
['X', 'x', 'J', '3905', 'p', '8349', 'R', '8409', '9985', '309', '9043', 'C', 'V', '3067', 'J', '7043', 'e', 'g']