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.
['5567', 'k', 'j', 'p', 'H', '1235', '4113', '9947', '9661', 'D', 'T', '2829', 'E', '8681', 'E', 'z', '3813', '5863', '9217', '43']