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: ['6055', 'v', '9455', 'A', '6817', 'D', '9339', 't', 'K', '1993']
Example Output: 33659

Example Input: ['4401', 'p', 'V', 'l', 'H', '7329', 's', '4717', 'l', '1773', '67', '179', 'l', '6991', 'a', '9377']
Example Output: 34834

Example Input: ['R', 'h', 'N', '6713', '1881', '7713', '4659', '413']
Example Output:
21379