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: ['R', 'J', 'z', 'o', '1121', '7247', '8987', 'u']

Answer: 17355


Question: ['4389', '8535', 'D', '6063', 'z', 'r', 'w', '5725', '291', 'a', '9059', '569', '2943', 'W']

Answer: 37574


Question: ['4283', 'r', 'M', 'C', '75', 'P', '2945', 'H', '2001', 'b', '131', 'y', '5271', 'G', 'R', 'L', 'R', 'b']

Answer:
14706