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: ['6469', '3027', 'Z', '3353', 'a', 'S', '3879', '8471', 'H', 'I', 'y', '2661', '9007', 'D']
Example Output: 36867

Example Input: ['A', '771', 'Q', 'b', '9929', '4991', 'q', '9863', '4363', '5721', 'C', '991', 'j', 'r', 'Q', 'B', 'K']
Example Output: 36629

Example Input: ['k', '2331', '8823', 'd', '2699', 'V', 'm', 'S', 'K', '6463']
Example Output:
20316