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: ['4607', 'T', 'a', '6077', 'c', '4761']
Example Output: 15445

Example Input: ['6629', 'o', 'e', '497', '4865', '8733', '5733', '7337', 'N']
Example Output: 33794

Example Input: ['c', 'q', 'm', 'M', '501', '5851', 'k', '973', 'g', 'i', 'z', 'M', 'J', 'W', 'O', '2299', 'C', '9701', '839', 'E']
Example Output:
20164