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: ['V', '8137', 'b', 'k', '2081', 'L', '9733', '7525', 'D', '2381', 'O']
Example Output: 29857

Example Input: ['t', '7469', 'Y', 'N', '8137']
Example Output: 15606

Example Input: ['3841', '2627', 'I', '3069', 'C', '7001', '2101', '9439', 'd', '9109']
Example Output:
37187