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: ['j', 'R', '2435']

Answer: 2435


Question: ['z', 'E', 'u', '4437', '7767']

Answer: 12204


Question: ['7889', '5903', '9199', 'J', 'R', '8907', '6899', 'J', 'i', 'G', 'E', '7949']

Answer:
46746