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.
['8681', '7297', '817', 'c', 'X', 'F', 'h', 'W', '4045', 'd', 'A', '8677', 'l', '4231', '4671', 'E', 'P', 'm']