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.
['1671', '8965', '3581', 'A', '365', '999', 'l', 'y', 's', '9289', '2685', '543', '1585', '2195', '1167', '5877', 'N', 'f']