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: ['u', 'W', '1561', '9243', '4923', '9385']
Example Output: 25112

Example Input: ['9905', 'm', 'Q', 'S', 'T', '7821', '1773', '9515', '3963', '2931', '7023', '8677', '1739', 'O', '909', '9153', '8319', 'k', '2851']
Example Output: 74579

Example Input: ['O', 'z', 'u', 'p', '7877', '5519', 'B', 'M', '3733', '6533', 'Y', '4699', '7173', 's', 'a']
Example Output:
35534