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: ['k', '4991', '7289', '4355', 'I', '8415', '5175', '5329', 'G', 'a', '7193', 't', '8821', 'j', '7239', '405', 'y', 'O', '9881', 'w']
Example Output: 69093

Example Input: ['r', '6537', '3001', '7879']
Example Output: 17417

Example Input: ['o', 'E', 'O', 'f', 'Z', 'E', '9577', 'P', '8745', '8291']
Example Output:
26613