instruction:
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.
question:
['2975', '33', '2845', '4695', 'j', '607', 'e', 'z', '6339', '1899', 'q', 'O']
answer:
19393


question:
['l', 'V']
answer:
0


question:
['1543', 'M', '4089', 'c', '7977']
answer:

13609