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: ['h', '2335', '2669', '6035', '9901', '7721', 's', '6181', 'C', 'l', 'x', '8275', '1103', 'S', '6447']
Example Output: 50667

Example Input: ['7087', 'P', 'i', 'e', '4875', 'e', 'F']
Example Output: 11962

Example Input: ['Q', 'O', '8405', 'G', '6885']
Example Output:
15290