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.

['9903', 'H', '757', 'J', '6481', '9789', 'H', '3285', 'V', 'X', '5229', '7197']
42641

['1319', '6105', '1119', 'c', 'p', '7617', '5113', 'a', '5115', '6731', '6693']
39812

['L', 'T', '8063', '7909']

15972