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', '3537', 'T', '3611', 'k', '4983', 'h', '4317', '8727', 'E', '6471', '8465', 'f', '5429', 'T', '2169', '2171', 'P', '6941', 'D']
Example Output: 56821

Example Input: ['6585', '5263', '9497', '1117', 'a', 'F', 'w', '6595', '547']
Example Output: 29604

Example Input: ['8897', '8897', '4327', 'Z', '553', 'D', 'u', 'G', '1395', 'W', 'k', '9027', 'P', 'H', '6063', 'x']
Example Output:
39159