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: ['1391', '1719', '8547', 'x', 'a', 'j', '6395', 't', '3421', '6607', 'M', '1645', 'H', 'x', 't']
Example Output: 29725

Example Input: ['v', 'Y', '4135', '8645', '263', '5377', '8677', 'Z', 'W', 'g', 'n', 'r', 's', '8513', '5677', 'u', '3033', 'I']
Example Output: 44320

Example Input: ['a', '4115', '9335', '7229']
Example Output:
20679