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: ['g', 'M', 'I', 'V', '3377', '7309', '3617', 'v', '9207', 'k', '387', 'g', 'C', '4785', '1527', 'O', 'A']
Example Output: 30209

Example Input: ['1815', 'U', '869', 's', '1847', 'C', '2711', 'S', 'i', '7949', '4477', '5093', 'D', '8661', '3835', '4087', '73', 'V', '3149', 's']
Example Output: 44566

Example Input: ['4457', 'B', 'i', '5115', 'U', '4173']
Example Output:
13745