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: ['s', 't', 'W', '163', 'v']
Example Output: 163

Example Input: ['F', '1221', '7179', 'r', '8231', 'k', '3069', 'L', '5301', '3209', '283', '4539', 'm']
Example Output:
33032