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.
['5477', '1035', 'E', '2647', 'V', 'W', '4309', '2409', 'y', '1981', '6909', '9201', '4205', 'D', '8007', '3683', '7915', '1719']