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

SOLUTION: 39304

PROBLEM: ['q', 'N', 'y', '7859', 'u', '2861', '4151', 'Q', 'x']

SOLUTION: 14871

PROBLEM: ['8657', '7627', '4919', '5727', 'T', 'k', '3329', '1121']

SOLUTION:
31380