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: ['A', '9775', '5867', 'n', '1329', '5973']
Example Output: 22944

Example Input: ['6255', '8457', 'V', 'z', '4405', 'X', '9267', '5329', 'I']
Example Output: 33713

Example Input: ['Q', '4477', 'h']
Example Output:
4477