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.

Example Input: ['v', 'Y', '4135', '8645', '263', '5377', '8677', 'Z', 'W', 'g', 'n', 'r', 's', '8513', '5677', 'u', '3033', 'I']
Example Output: 44320

Example Input: ['h', '2335', '2669', '6035', '9901', '7721', 's', '6181', 'C', 'l', 'x', '8275', '1103', 'S', '6447']
Example Output: 50667

Example Input: ['u', '7015', '5423', '7807', 'k', 'Z', '1925']
Example Output:
22170