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: ['D', 'P', 'y', '4891', '1539', 'J', '5737']
Example Output: 12167

Example Input: ['2913', 'b', 'j', '7591', 'O', 's', '5589', '4995', '7503', 'U', 'S', 'C', '6797']
Example Output: 35388

Example Input: ['E', 'X', 'C', 'v', '2803', 'g', 'b', '763']
Example Output:
3566