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

Example Input: ['o', '7099', 'G', 'v', 'H', 'J', 'k', '1607', 'i', '9765', '2489', '8031']
Example Output: 28991

Example Input: ['h', '2999', 'f', '1327', '4511', 'O', '5751', '9439', 'e']
Example Output:
24027