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: ['j', '6731', 'h', 'G', 'F', '6899', '4317', 'm', '9491', 'l', '971']
Example Output: 28409

Example Input: ['2895', '8095', 'y', '1927', '4827']
Example Output: 17744

Example Input: ['6369', '4107', 'P', 'O']
Example Output:
10476