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: ['2485', 'Q', 'G', '5533', 'Y', '21', 'D', 'S']

Answer: 8039


Question: ['4177', 'd', 'b', 'm', 'f', 'R', '797', '7905', '4355', '7515', '9801', 'F', 'R', '9125', '8445', 'k', 'K', 'K']

Answer: 52120


Question: ['r', '6537', '3001', '7879']

Answer:
17417