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: ['6161', 'p', '2839', 'c', '5905', '1729', 'j', '5901', '3013', 'e']
Example Output: 25548

Example Input: ['R', 'k', '3355', 'Y', '6635', 'M', '4839', 'T', 'd', '495', 'g', 'E', 'g', 'F', 'S', '5377', 'g']
Example Output: 20701

Example Input: ['1891', 'G', '3491', 'C', '5509', 'n', '9699', '4497', '8761', '6309', 'B', 'G']
Example Output:
40157