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: ['E', 'y']
Example Output: 0

Example Input: ['U', '5607', 'Q', 'j', 'I', '3745', '3031']
Example Output: 12383

Example Input: ['599', 'c']
Example Output:
599