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

['3895', 's', 'j', '7755', 'H', '7941', '4903', 's', '3629', '1183', '1001', '5569', 'q', '4735']
40611

['359', 'C', '5555', 'L', '8315', '1621']

15850