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: ['Q', 'v', 't', '223', 'm', 'l', 'c', 'M', 'b', '2227', 'P', 'e', 'n', 'f', 'S', '2205', '3517', '5545']
Example Output: 13717

Example Input: ['6629', 'o', 'e', '497', '4865', '8733', '5733', '7337', 'N']
Example Output: 33794

Example Input: ['261', 'V', 't']
Example Output:
261