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: ['s', '3607', 'p', 'P', '9285', 'J', 'l', '9863', '9823', '2817', 'g', '9751', '599', '2605', 'k', 'Y', 'O', 'U', '9649']
Example Output: 57999

Example Input: ['6001', '6423', '5591', '8721', 't', 'x', '3723', 'E', 'F', '7353', 'b']
Example Output: 37812

Example Input: ['N', 'O', 'V', 'x', 'p', '5083', '4147', 'x', 'K', '1739', 'v', '5443']
Example Output:
16412