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.
['8625', 'D', '3377', '9633', 'f', '7915', '3077', 'e', 'K', '473', '5607', '9945', '4153', 'M', '5455', '4303', 'w', '6527', '2449']