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: ['c', 'r', 'R', 'a', '6915', 'C', '3651', 'j', 'L', '9761', '2923', 'Z', 'e', '833', 'W', '1867', 'G', 'H', 'T']

Answer: 25950


Question: ['l', 'B', 'Y', '7543', '5091', '1917']

Answer: 14551


Question: ['6455', '5805', '2035', 'A', 'I', '7721', 'I', 'P', '4069', '2409', 'n', 'm']

Answer:
28494