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: ['3331', '5791', 'r', 'Q', '2243', '8229']
Example Output: 19594

Example Input: ['I', 'J', 'K', 'D', '5961']
Example Output: 5961

Example Input: ['1179', '5855', '8115', 'R', '1337', 'G', 'z', 'k', '9475', 'Y', '3517', '5729', 'C', '7717', '7219', '1987', 'C']
Example Output:
52130