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:
['d', '4553']
answer:
4553

question:
['F', 'E', '339', '1855']
answer:
2194