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', 'S', 'H', 'e', 'o', 'i', '6953', '5121', '6391', '8931', 'b', '7111', '4847', '6715', 'L', '4181', 'l', 'q', 'v', 'j']