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

Example Input: ['n', 'W', '565', '6625', '903', 'o', '7995', '8339', '5251', 'e', 'a', '1081', '5813', 'o']
Example Output: 36572

Example Input: ['P', 'X', 'u', 'B', 'G', 'P', 'C', '3453', '1927', '8779', '7875', 'l', 'I', '3415', '2997', 'O', '4555', '9533', 'd']
Example Output:
42534