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: ['q', '5151', 'R', '441']
Example Output: 5592

Example Input: ['29', 'N', '5061', '7191', 'z', '8367']
Example Output: 20648

Example Input: ['w', 'f', '3539', '9215', 'b', '9993', 'j', 'y', '807', '1301', '3359', 'N', '5853', 'S', 'l', '2665', '1673']
Example Output:
38405