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.

['6321', 'M', 'd', '3673']
9994

['d', 'b', 'W', '3201', 'C', 'o', '5187', '9723', '8177', 'F', '6703', 'U', '1393', '1035', '3507', '5993', '3857', 'r', 'C', 'j']
48776

['f', 'B', 'Q', '893', '8021']

8914