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.
['A', '7681', '2269', '17', '2607', '4967', '6333', '1867', '1079', '9663', '1241', 'v', 'b', '5725', 'S', 'T', 'J', 'C', '5275']