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:
['Y', '9053', 'N', '6921']
answer:
15974


question:
['R', 'I', 'f', 'K', 'p', '8579', 'e', '1223', 'I', 'K', '8311', '2147', '4241', 'z', '6671', 'r']
answer:
31172


question:
['t', '2419', '3119', '5971', '7775', 'A', '951']
answer:

20235