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: ['7771', 'g']

Answer: 7771


Question: ['2913', 'b', 'j', '7591', 'O', 's', '5589', '4995', '7503', 'U', 'S', 'C', '6797']

Answer: 35388


Question: ['2103', '4753', '7999', '6853', 'K', '4635', 'k', '6955', '3077', '9721', '5935', 'a']

Answer:
52031