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: ['S', 'D', '3101', '4967', '8197', '5025', '4257', 'S', 'X', '7641', 'n', '6775', '4719', 'o', '2821', 'x', '5605', '2181']
Example Output: 55289

Example Input: ['B', 'K', '9399', 't', '5541', 'w', '1939', '7841', 'q']
Example Output: 24720

Example Input: ['5475', 'L', '2395', '2153', 'y', 'j', 'v', 'Z', '1127']
Example Output:
11150