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: ['B', '9189', '3691', '2869', '1525', 'd', 'H', 'P', '8613', 'b', 'r', '5289', 'V', '6433', '8733', 'K', '8105', '1041', 'U', 'L']
Example Output: 55488

Example Input: ['s', '9377', '3663', '1375', 'j', 'L', '7943', '1711', '7409', '9115', '1227', 'I', 'U']
Example Output: 41820

Example Input: ['x', 'H', '8367', '3573', '4739', '1157', 'l', '2947', 'l', '4347', 'Y', 'B', 'l', 'S', 'u', '5407', 'N']
Example Output:
30537