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: ['339', 'h', 'd', '7449', 'e', 'u', '5055', '7029', '9009', 'G', 'U', '3', '441', '3273', 'K', '3827', '7069', 'x']
Example Output: 43494

Example Input: ['f', 'H', 'U', 'l', 'n', 'q', '2701', '339', 'X', 'H', 'O', 'q', '2313']
Example Output: 5353

Example Input: ['1413', '8233', '57', '2155', 'Y', '4899', 'e', 'G', 'T', '5417']
Example Output:
22174