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: ['R', '9751', '4367', 'l', 'N', '5125', '8751', '7507', 'y', 'K', '6127']
Example Output: 41628

Example Input: ['g', 'A', 'r', '539', '5459', '2725', '7447', '3693', '1757', 'r', 'W', '5949', '4569', '5153', '3985', 'Q', '505', 'M', '8989']
Example Output: 50770

Example Input: ['p', 'X', '8087', '223', 'P', 'm', '2275', '9135', '7181', '4669', '9795', '5877', '4097', 'D', '4087', 'r']
Example Output:
55426