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.
['p', 'L', 'Z', '4167', 'I', '7149', '4413', 'U', '9941', '169', '2425', 'J', '897', 'x', '5169', '7445', '417', 'Y', '4255']