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: ['3873', 'D', 'J', '2799', 'k', 'F', 'I', '3457', '5647', '4815', '7509', 'Y', '1251', '2211']
Example Output: 31562

Example Input: ['5347', 'E', 'a', '5379', '405', '1171', 'v', 'J']
Example Output: 12302

Example Input: ['5411', '9789', 'P', 'E', 'Y', 'u', '7559', 'B', 'q', '5405', 'H', 'q', '7853', 'w', '3605', 'N', 'U', '8131']
Example Output:
47753