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: ['6577', 'Q', '6865', '7671', 'N']
Example Output: 21113

Example Input: ['29', 'N', '5061', '7191', 'z', '8367']
Example Output: 20648

Example Input: ['8353', 'f', '1799', '6985', '2975', 'J', '9105', 'f', 'v', 'C', 'V', '9327', '3015', 'e', 'h', '439', '4969', 'c']
Example Output:
46967