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:
['7459', '491', '7823', '6965', 'H', '109', 'R', 't', '3959', '2821', 'R', '2807', 'o', 'v', '1305', 'a', '1411', 'r', '3669']
answer:
38819


question:
['4425', 'x', '1959', 'C', 'c', 'D', 'M', '8317', 'q', 'x', '4277', 'N', 'z', 'I', '1921', 'o', 't']
answer:
20899


question:
['Q', 'o', '9717', 'W', '5419', 'C', 'v', 'S', '1601', '9923', '6063', 'D', '5191', '775']
answer:

38689