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

Example Input: ['j', '3779', 'X', '7775', '2397', '7713', 'd', '915', '5147', '2435', '2783', 'O', '3783', 'Q', '5543', 'k', 'f', 'y', '8775']
Example Output:
51045