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.
['R', 'G', 'x', '6625', 'f', '9065', '5287', '6745', '3061', 'Y', 'G', 'R', '3617', '1707', 'B', '2401', '9733', 'X']