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.
['8689', 'H', 'F', '1021', '1003', '9803', 'v', '9901', '8183', '2645', '3309', '5653', 'y', '2645', 'o', 'L', '5993', 'g', '3069']