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: ['1073', 'i', 'o', 'j', 'O', 'g', 'X', '3261', '5105', '4831', 'J']
Example Output: 14270

Example Input: ['3497', '761', '6157', 'J', 'n', '139', '9895', '2939', 'K', 'I', '2161', 'c', 'a', '485', '7959', 'i', '4753', '3305', 'G', '3475']
Example Output: 45526

Example Input: ['A', 'W', '4439', '4345', 'j', '8247', 'X', 's', '6717', 'c', '1319', 'Q', 'm', '5931', '425', '6903', '1141', 'U']
Example Output:
39467