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: ['8683', 'p', '47', '8983', 'g', 'u']
Example Output: 17713

Example Input: ['507', 'P', '9697', 'u', '5057']
Example Output: 15261

Example Input: ['2651', 'R', 'w']
Example Output:
2651