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: ['r', 'B', '8791', '3165', 'n', 'm']
Example Output: 11956

Example Input: ['7419', 'Q', '5933', '6779', 'p', '7797', 'y', 'E', '1451', 'n', 'c', '491', 'N', '6959', '9477', '749', '7357', '7059', 'o']
Example Output:
61471