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: ['3331', '5791', 'r', 'Q', '2243', '8229']
Example Output: 19594

Example Input: ['V', '8137', 'b', 'k', '2081', 'L', '9733', '7525', 'D', '2381', 'O']
Example Output: 29857

Example Input: ['3565', 'M', 'i', '6283', '7107', '8053', 'u', '7911', '5709', '8417', 'C', '1521', '3561', '9801', '6431', 'c', '1301']
Example Output:
69660