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: ['6867', 'x', '8481', '5091', '979', 'a', 'S', 'i', 'd', '1591']
Example Output: 23009

Example Input: ['6787', 'W', 'I', '4929', 'j', 'I', '3487', 'F', '3927', 'Q', 's', 'X', '9939', 'n']
Example Output: 29069

Example Input: ['3947', 'F', 'V', 'M', '7843', '4525', 'Y', '8571', 'O', 'D', '3285', '1065', 'f', '5191', 'G', '317', 'x', 'd']
Example Output:
34744