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: ['g', 'M', 'I', 'V', '3377', '7309', '3617', 'v', '9207', 'k', '387', 'g', 'C', '4785', '1527', 'O', 'A']
Example Output: 30209

Example Input: ['8553', 'Y', 'h', '481', '2049', 'L', '5843', '8501', 'S', '7421']
Example Output:
32848