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.
['V', 'X', '6223', 'M', 'g', 'A', 'B', '7193', '8791', 'y', '7833', 'E', 'q', '5389', 'M', '2639', '2019', 'X']