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.
['4241', '3497', 'o', 'a', 'K', '2495', 'v', 'R', '677', 'e', 'o', 'p', '5267', 'W', 'I', '1165', '2447', '3025', 'b']