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: ['4701', 'b', 'i', 'B', 'z', '7837', 'W']

Answer: 12538


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

Answer: 52120


Question: ['n', 'j', '2539', '203', 'N', 'G', 'Z', 'g', '5683', 'l']

Answer:
8425