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: ['r', 'z', 'u', 'D', '3449', 'E', 'f', 'w', '1627', '4093', '955', 'i', 's', 'R', 'b', '9773', '2169', 'M', '9305', '4775']

Answer: 36146


Question: ['8267', '3859', 'H', '9971', '9475', 'x', '5241', '3337', 'q', '9077', '1503', '5773']

Answer:
56503