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.

['6019', '1467', '3415', '7785']
18686

['4425', 'x', '1959', 'C', 'c', 'D', 'M', '8317', 'q', 'x', '4277', 'N', 'z', 'I', '1921', 'o', 't']
20899

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

42641