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: ['9903', 'H', '757', 'J', '6481', '9789', 'H', '3285', 'V', 'X', '5229', '7197']
Example Output: 42641

Example Input: ['z', 'c', 'E', 'Q', '1839', 'g', 'X', 'c', '291', 'c', 'w', 'e', '5957', 'X', '6471', 'A', '8359', 'y', '3611', '5417']
Example Output: 31945

Example Input: ['6225', '8821', '7183', '2439', 'w', '1457', '7449', '3803', '7681', 'k', '4045', 'v', '5903', 'q', 'q', '5183', 'k', 'Y', 'B', '7179']
Example Output:
67368