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: ['773', 'e', '4451', 'S', 'I', 'r', 'e', 'V', 'Q', 'g', 'J', 'L', '7655', 'O']

Answer: 12879


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

Answer: 19393


Question: ['M', '7977', 'o']

Answer:
7977