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: ['9403', '2607', 'G', '7901', 'K', '7967', 'a', 'n', '1967', 'x', 'g', '1081']
Example Output: 30926

Example Input: ['3895', 's', 'j', '7755', 'H', '7941', '4903', 's', '3629', '1183', '1001', '5569', 'q', '4735']
Example Output: 40611

Example Input: ['r', 'O', 'n', 'X', '4405', '2825', 'G', 'i', 'M', 'v', 'A', '7065', 'j', 'K', '1115', '2607']
Example Output:
18017