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: ['P', '237', 'X', '8893', '7931', 'F', '8359', 'S', '6931', '6953', 'r']

Answer: 39304


Question: ['J', '177', '8449', '2067', 'a', 'G', 'p', 'd', '5161', 'M', '2403', '5541', 'q', '4375', 'O']

Answer: 28173


Question: ['9301', '3399', 'E', '8873', '9731', 'R']

Answer:
31304