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: ['4089', '2385', 'E', 'K', '259', '295', '6649', '8645', 'n', '2577', '2683', '9041', 'Q', 'm', '4237']
Example Output: 40860

Example Input: ['n', 'G', '5059', '8343', '8673', 'P', 'N', '5485', '2279', '6121', 'i', 'U', '7277', '8701', 'A', 'b', 'Z', 'R', '6371', 'G']
Example Output: 58309

Example Input: ['2121', '7729']
Example Output:
9850