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: ['h', '2295', '2913', 'I', '5273', 'L', '2739', '8227', '6537', 'e', '6491', '5463', 'i', '4337', '537']
Example Output: 44812

Example Input: ['B', 's']
Example Output: 0

Example Input: ['c', '8173', 'E', '4801', '3627', '9097', '6965', '5209', 'k']
Example Output:
37872