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', '8841', 'H', 'v', '2435', '8221', '807', 'P', '2247', 'M', '4609', '5657', 'k', '2807', 'j', '8451']
Example Output: 44075

Example Input: ['X', 'P', 'x', '9471', '5', 'c', 'f', '5077', '1085', '2267', 'R', 'q', '4987', '9529', 'H', 'n', 'r', 'u']
Example Output: 32421

Example Input: ['4317', '3357', 'n', '197', 'd', '1655', 'I', '7231', '2255', '4683', 'K', '8247', 'E', 'F', 'g', 'y', '9565', '9001']
Example Output:
50508