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: ['a', 'j', 'v', '619', 't', 'a', '5777', 'x', 'R', 'P', '8897', 'j']
Example Output: 15293

Example Input: ['1693', '9237', '7591', '1593', 'R', '6295', '9379']
Example Output:
35788