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.
['v', 'y', '2085', 'y', 'P', 'X', '2217', '4897', 'O', 'c', 'u', '9153', 'T', 'b', 'z', '9321', 'K', '1499', 'I']