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: ['3883', 'T', '6175', 'B', '4365', '3719', 'V', 'B', '3173', 'K', 'Z']
Example Output: 21315

Example Input: ['9905', 'm', 'Q', 'S', 'T', '7821', '1773', '9515', '3963', '2931', '7023', '8677', '1739', 'O', '909', '9153', '8319', 'k', '2851']
Example Output: 74579

Example Input: ['5613', '1563', '7503', 'B', '8695', '7683', 'U', 'g', '5733', 'O', '4801', '1143']
Example Output:
42734