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.
['t', 'V', '8093', '8109', 'K', '9193', 'p', 'c', '4539', '9879', '6047', '4411', 'Y', 'y', '1899', '6499', '4653', 'h', '4311']