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: ['3145', 'C', '7725', 'k', 'z']

Answer: 10870


Question: ['r', 'z', 'u', 'D', '3449', 'E', 'f', 'w', '1627', '4093', '955', 'i', 's', 'R', 'b', '9773', '2169', 'M', '9305', '4775']

Answer: 36146


Question: ['6917', '5891', '8677', 'f', '9755', '9629', '6961', 'F', '7', '5791', 'O', '6745', '2041', '9885']

Answer:
72299