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.
['5887', 'h', 'E', '7185', '1487', 'x', 'e', 't', '1295', 'A', '8129', '8799', '155', '1965', 'N', 'K', 'h', '1251']