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

Example Input: ['q', 't', '4837', 'F', '2367', '1867', '8361', 'm']
Example Output: 17432

Example Input: ['X', 'A', '2655', 'a', '6763', '2101', '5191', '7665']
Example Output:
24375