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: ['o', 'O', 'H', '7619', '6435', 'X', 'g', '1663']
Example Output: 15717

Example Input: ['k', '1489', 'x', '6543', 'I', 'l', 'D', '6299', '1473', 'a', '7661', 'z', 'E', 'Z', 'U', '3671', '2873', 'e', 'p']
Example Output: 30009

Example Input: ['Q', '3287', '3981', 'P', '107', '3265', '7001', '6075', '8123', 'G', '1841', '2367', '7599', 'B', 'k', '1277', 'U']
Example Output:
44923