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: ['z', 'U', '6817', 's', '3731', 'M', 'I', '1095', 'l', '5993', '5207', 'e', 'L', '5361', 'v', 'g', '1963', '4829', '9541', '8261']
Example Output: 52798

Example Input: ['D', '8591', 'b', 'n', 'e', '883', '8923', '245', 'z', '5643', 'C', '2911', '9275', '711', '7299', '3449', '4799', '6065']
Example Output: 58794

Example Input: ['5113', 'a', '6709', '5663', 'P']
Example Output:
17485