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: ['j', 'R', '2435']
Example Output: 2435

Example Input: ['8311', '3565', 'h', 'A', 'K', '821', 'p', '3117', 'o', '9699', '4501', '1009', 'L', 'k', '9533', 'm', '7175', '6411']
Example Output:
54142