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.
['N', 'B', '1289', 'J', 'a', '1491', 'k', '265', '2607', 'V', '2655', 'w', 'T', '7341', 'A', 'F', '551', '1741', '2239', 'd']