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.
['b', 'u', 'n', 'e', '9155', '9971', 'W', 'K', '5269', 'M', '7193', '7193', 'y', '1967', 'S', 'T', 'Q', '2013', '1293']