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.
['q', 'K', '8833', 'I', 'J', '3195', 'v', 'y', 't', '567', '6705', 'D', '5983', 'J', 'R', 'i', '4435', 'Q', '8619', '5197']