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: ['l', 'B', 'Y', '7543', '5091', '1917']
Example Output: 14551

Example Input: ['t', 'v', 'B', 'Y']
Example Output: 0

Example Input: ['p', '1435', '4831', 'L', 'E', '2797', '9069', 'X', 'X', '5373', 'i', '9009', '79', 'd', 'e', '685']
Example Output:
33278