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', 'E', 'M', '1303', 'y', 'H']
Example Output: 1303

Example Input: ['K', 'p', '97', 'R', '2999', 'u', '7307', '6033', '6431', 'm', 'T']
Example Output: 22867

Example Input: ['6385', 'i', 'H', '2483', '17', '8881']
Example Output:
17766