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: ['D', 'm', 'P', '2433', '6731']
Example Output: 9164

Example Input: ['R', '3361', 'c', 'S', 'g', '3829', '7347', '6633', 'e', '9227']
Example Output: 30397

Example Input: ['4411', 'V', '5013', 'j', '7023', '2555', '443', 'o', '6301', 'r', '485', 'J', 'B', 's', 'p', 'N', '3273', '6825', '4597', 'b']
Example Output:
40926