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.
['b', '9625', '239', 'l', '6915', 'n', 'Z', 'k', '5109', 'v', 'w', '7065', 'F', 'r', '4805', '4451', '9111', 'r', 'C']