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: ['D', 'R', 'Y', '4929', 'P', '7929']

Answer: 12858


Question: ['2975', '33', '2845', '4695', 'j', '607', 'e', 'z', '6339', '1899', 'q', 'O']

Answer: 19393


Question: ['6179', '2303', '6163', 'V', '6561', '5053', 'c', '3407', 'E', '6179', '9043', '5315', '1089', 'h', 'o']

Answer:
51292