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', 'h', '5549', 'K', 's', '8337', 'Y', '497', 'z', 'T', '4467', '6333', 'M', '1573', 'y', 'O', '5499', 's', 't', '6205']