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: ['8667', '4129', '7075', '6345', '1315', 'M', 'F', '9073']
Example Output: 36604

Example Input: ['q', '6631', 'b', '4207', '7523', '9853', '9203', 'P', '5029', 'b', '2319', '4717', '2485']
Example Output: 51967

Example Input: ['8893', 'z', '2979', 'a', '6175', 'i', 'P', 'w', 'G', 'M', '2537', '8319']
Example Output:
28903