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.
['2237', '2597', '2593', 'Y', '5345', 'g', 'l', 'I', 'p', 'u', 'L', 'T', '617', '9759', 'b', 'w', '7097', '9863']