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: ['2325', '3259', '1947', '8065', 'H', '2329', 'h', 'l', 'k', 'R']
Example Output: 17925

Example Input: ['6731', 'f', '4561', '5601', 'i']
Example Output: 16893

Example Input: ['l', 'o', 'M', 's']
Example Output:
0