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:
['T', 'n', '8513', '5565', '6343', '1403', '975', '6959', '8049', '1601', 'j', 'Q', 'O', '7889', 'r', 'D', '1903', '6607']

Ex Output:
55807


Ex Input:
['901', 'X', 'W', 'D', 'm', 'M', '59', '4855', '6523', 'R', '9781', '8271', '4449', '2221', '8391']

Ex Output:
45451


Ex Input:
['R', '5231', 'a', 'u']

Ex Output:

5231