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: ['h', '2295', '2913', 'I', '5273', 'L', '2739', '8227', '6537', 'e', '6491', '5463', 'i', '4337', '537']
Example Output: 44812

Example Input: ['X', '989', 'U', '9551', '6385', 'Y', '1433', 'J', '1833', '685', 'u']
Example Output: 20876

Example Input: ['K', 'u', 'P', 'R', 'R', 'L', '949', '6743', '6247', 'q', 'x', 'T', 'Y', '5923', '4155', '5633', 'r', 'K', 'U', '893']
Example Output:
30543