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: ['7231', '2813', '51', '1745', 'c', 'a', '4929', '3185', '5707', '2095', 'f', 'S']
Example Output: 27756

Example Input: ['2975', '33', '2845', '4695', 'j', '607', 'e', 'z', '6339', '1899', 'q', 'O']
Example Output: 19393

Example Input: ['y', 'n', '4433', '2471', '4613', 'O', '5965', 'A', '7113']
Example Output:
24595