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: ['9989', 'B', 'E', '5181']
Example Output: 15170

Example Input: ['A', 'y', 'u', 'S']
Example Output: 0

Example Input: ['3843', 'O', '459', '3537', 'h', '3083', '4911', '2173', '1311', '1467', 'W', 'B', '507']
Example Output:
21291