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: ['f', 'H', 'U', 'l', 'n', 'q', '2701', '339', 'X', 'H', 'O', 'q', '2313']
Example Output: 5353

Example Input: ['A', '9775', '5867', 'n', '1329', '5973']
Example Output: 22944

Example Input: ['O', '6395', 'z']
Example Output:
6395