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: ['C', '9973', 'b', '693', 'y', 'H', 'C', 'P', 'b', 'J', 'f', 'T', '2317', 'O', '5755', '8201', 'p', 'y', '8721', 'i']
Example Output: 35660

Example Input: ['6019', '1467', '3415', '7785']
Example Output: 18686

Example Input: ['C', '8019', 'e', 'S', 'C', '6565', '3231', '3115', 'I', '4077', '637', '3995', '9297', 'U', 'c', 'p', 'n', '527']
Example Output:
39463