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: ['6723', '1', '6357', '1497', 'A', 'p', 'N', 'T']
Example Output: 14578

Example Input: ['M', '1589', '8353', 'X', 'P', '3173', 'V', '1335', 'm', 'l', '6421', '4823', 'r', '8941', '4255', '9107', 'z', '2449', '2321', 'l']
Example Output: 52767

Example Input: ['h', 's', 'r', '9581', 'Q', '3921', '5515', '737', 'j', '4139', '5955', '5315', 'C', '1733']
Example Output:
36896