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', '2119', '9145', 'Q', '4831', '6819', 'e', '3635', '523', 'v', 'o', '9439', 'n', 'h', '9879', 'e', 'h', 'N', 'b', 'H']