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: ['Q', '1669']
Example Output: 1669

Example Input: ['1845', '273', '6921', 'u', '165', 'n', 'y', 'I', 'u', 'X', '5503', 'L', 'G', 'V', '6223', '1123', 'v']
Example Output: 22053

Example Input: ['4021', '8423', '3719', '4993', '3593', 'n', '9807', 'Y', 'M', '3117', '7901', '1839', 'P', 'q', 'x', 'R', '9449', 'V']
Example Output:
56862