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: ['8591', 'J', 'l', 'l', '7023', 'N', 'n']
Example Output: 15614

Example Input: ['c', 'r', 'R', 'a', '6915', 'C', '3651', 'j', 'L', '9761', '2923', 'Z', 'e', '833', 'W', '1867', 'G', 'H', 'T']
Example Output: 25950

Example Input: ['P', '7745', 's', '8901', 'X', '5267', '3321', '1015', '4723', 'L', '5941']
Example Output:
36913