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.

['3145', 'C', '7725', 'k', 'z']
10870

['543', '8351', 'I', 'M', '6647', '731', 'b', 'r', 'l', '3935', 'k', 'z', 'v', '2131', '7781', 'X', '9419', '5013', 'F']
44551

['z', '5211', '893', 'L', 'L', 'a', '6557', '4203', 'Z', '2497', '2745', 'q', 'Y', '7321', '5935', '4573', 't', 'B']

39935