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:
['w', '2281', '8651', '2203', 'q', 'n', '4253']

Ex Output:
17388

Ex Input:
['Q', '8317', '8989']

Ex Output:
17306

Ex Input:
['9905', '9997', '4205', 'F', 'q', '5207']

Ex Output:
29314