Instructions: 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.
Input: ['u', '6631', 'i', '5775', '5567', 'E', 'W', '7005', 'z', '3547', '8223', 'a', '2235', 'J', '4685']
Output:
43668