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.
['9033', 'I', 'b', '8161', '2813', 'e', 'o', '793', '971', 'r', 'r', '9699', 'u', 'I', 'K', 'm', 'B', 'e', '5861']