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.
['939', 'g', 'r', 'i', '9659', '3049', 'r', 'V', 'a', '941', '681', 'c', '8293', 'z', 'p', '7811', 'o', '6265']