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

Example Input: ['29', 'N', '5061', '7191', 'z', '8367']
Example Output: 20648

Example Input: ['1377', 'Y', 'p', 'F', '7547', 'p', '5665', '8687']
Example Output:
23276