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: ['4241', 'E', '1807', '2877', '5125', '7625', 'S', '401', '5081', 'u', 'R', 'F']
Example Output: 27157

Example Input: ['D', '8591', 'b', 'n', 'e', '883', '8923', '245', 'z', '5643', 'C', '2911', '9275', '711', '7299', '3449', '4799', '6065']
Example Output: 58794

Example Input: ['6975', '1699']
Example Output:
8674