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: ['4701', 'b', 'i', 'B', 'z', '7837', 'W']
Example Output: 12538

Example Input: ['T', 'n', '8513', '5565', '6343', '1403', '975', '6959', '8049', '1601', 'j', 'Q', 'O', '7889', 'r', 'D', '1903', '6607']
Example Output: 55807

Example Input: ['9135', '9507', '8553', '5749', 'o', 'T', 'Z']
Example Output:
32944