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', 'x', '5629', 'k', '2003', 'v', '541', 'l', 'v', '7983', '677', '6173', 'z', 'J', 's', 'u', '2187', 'Y']