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: ['901', '1939', '7637', '8863', 'X', '5003', '8791', '4757', 'E', '1525', 'y', '9735']
Example Output: 49151

Example Input: ['7771', 'g']
Example Output: 7771

Example Input: ['4247', 'a', '3101']
Example Output:
7348