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:
['2915', '4443', 'Z', '3409', '1417', 'H', 'T', 'u', '3373', 'U', '115', 'R']
answer:
15672


question:
['4975', 'M', 'C', 'D', 't', 'i', 't', 'L']
answer:
4975


question:
['5617', 'v', '761', 'f', 'Y', '5925', '1399', 'l', 'c', 'a', 'y']
answer:

13702