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: ['6019', '1467', '3415', '7785']
Example Output: 18686

Example Input: ['Q', '8841', 'H', 'v', '2435', '8221', '807', 'P', '2247', 'M', '4609', '5657', 'k', '2807', 'j', '8451']
Example Output: 44075

Example Input: ['4301', 's', 's', 'X', 'u', 's', 'T', '9187', '5911', '273', 'k', 'w', '8923', '1259', 'z']
Example Output:
29854