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.

[EX Q]: ['4869', 'L']
[EX A]: 4869

[EX Q]: ['J', '177', '8449', '2067', 'a', 'G', 'p', 'd', '5161', 'M', '2403', '5541', 'q', '4375', 'O']
[EX A]: 28173

[EX Q]: ['S', '8153', 'U', '1315', 'l', '4595', 'S', '5799']
[EX A]:
19862