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: ['n', 'u', '9595', 'M', 'o', 'K', '5073', 'x']
Example Output: 14668

Example Input: ['543', '8351', 'I', 'M', '6647', '731', 'b', 'r', 'l', '3935', 'k', 'z', 'v', '2131', '7781', 'X', '9419', '5013', 'F']
Example Output: 44551

Example Input: ['U', '5607', 'Q', 'j', 'I', '3745', '3031']
Example Output:
12383