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: ['7959', '1345', '4605', '6453', 'Q']
Example Output: 20362

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: ['T', 't', 'e']
Example Output:
0