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.
['5855', '4249', '3521', '9185', 'B', '6183', '5871', 'E', '9517', '6345', 'Z', '125', 'q', 'A', 'v', 'I', '4671', '7797', '3281']