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.
['z', 'c', 'E', 'Q', '1839', 'g', 'X', 'c', '291', 'c', 'w', 'e', '5957', 'X', '6471', 'A', '8359', 'y', '3611', '5417']