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:
['6347', '5495', '169', '9503', 'H', '571', '6105', 'X', 'r', 'e', '7369', 'a', 'd', '6999']
answer:
42558


question:
['s', '9377', '3663', '1375', 'j', 'L', '7943', '1711', '7409', '9115', '1227', 'I', 'U']
answer:
41820


question:
['7469', '7867', 'D', 'x']
answer:

15336