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: ['1203', '6179', '9835']
Example Output: 17217

Example Input: ['2577', 'B', '3059', 'S', 'l', 'T', 'Q', 'x', 'f', 'l', 'y']
Example Output: 5636

Example Input: ['S', '6277', '1359', '6101', '4201', 'k', '9255', '839']
Example Output:
28032