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: ['4685', 'q', 'O', 'o', '3453', 'o', 'Y', 'C', 'a', 'i', '7283', 'J', 'n', 'Q', 'i']
Example Output: 15421

Example Input: ['q', '5151', 'R', '441']
Example Output: 5592

Example Input: ['K', 'q', 'y', 'g']
Example Output:
0