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.

['9403', 'u', '4159', 'w', '3467']
17029

['6815', 'A', '1055', '4687', '8675', '4615', 'a', '2127', 'w', 'l', 'J', '5025', 'c', 't', '9727', 'G', '8431']
51157

['8251', 'C']

8251