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 Input:
['s', 'M', 'U', '5383']

Ex Output:
5383


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

Ex Output:
20899


Ex Input:
['i', 'f', 'c', '923']

Ex Output:

923


