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: ['6577', 'Q', '6865', '7671', 'N']

Answer: 21113


Question: ['Q', '6383', 'P', '8455', '3881', '5821', 'e', 'v', '1421', 'Q', '6377', '3157', '6407', 'q']

Answer: 41902


Question: ['b', '7735', '4285', 'Z', '533', '8543', 'X', '3887', '3813', '493', 'y']

Answer:
29289