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.

['7459', '491', '7823', '6965', 'H', '109', 'R', 't', '3959', '2821', 'R', '2807', 'o', 'v', '1305', 'a', '1411', 'r', '3669']
38819

['7379', 'I', '2031', '8419', 'w', 'b', '9827', 'X', 'Y', 't', '3789', 'B', 'c', '6599', 'F', '6169', 'V']
44213

['9869', '7581', 'D', '875', 'a', 'v']

18325