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: ['8683', 'p', '47', '8983', 'g', 'u']
Example Output: 17713

Example Input: ['5331', 'f', '2865', '6019', 'U', 'm', 'g', 'n', 'Y', 'A']
Example Output: 14215

Example Input: ['1715', 'p', 'e', '6967', '6641', 'W', '6267', '8653', 'R', '1687', '8913', 'N', 'f', 's', 'b', '3373', '3931', '6699']
Example Output:
54846