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', 'm', 'P', '2433', '6731']
Example Output: 9164

Example Input: ['b', '5447', 'R', '8489', 'L', '627', 'P', '7491', 'c', 'c', 'r', '6923', '1167']
Example Output: 30144

Example Input: ['A', 'V', 'B', '6263']
Example Output:
6263