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.
['O', 'L', 'p', '6995', '4551', 'm', 'g', '8601', 'z', '1759', '9867', '2847', '4185', 'g', 'e', 'R', 'Z', '1273', 'J', 'L']