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: ['6255', '8457', 'V', 'z', '4405', 'X', '9267', '5329', 'I']
Example Output: 33713

Example Input: ['x', 'd', '5121', 'I', '6737', '3789', '6167', 'C', '8947', 'k', '4715', '1885', 'H', 'B', '5685', 'S', '4615', 's', '7709']
Example Output: 55370

Example Input: ['3015', '7227', 'Y', '8149']
Example Output:
18391