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

Example Input: ['f', '6703', 'c', 'c', 'l', '2511', '6507', 'b', '9727', 'l', '1251', 'I', '5231', '91', 'L', 'M', 'd']
Example Output: 32021

Example Input: ['N', '9483', '843', 'J', 'F', 'b']
Example Output:
10326