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.

['i', 'C', '5373', '2017', 'm', '5435', 'Y', 'h']
12825

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

['t', '4471', '6139', '4447', 'C', 'C', 'M', 'U', '4869', '9563']

29489