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: ['M', 'H', 'l', 'Y', '3811', '1953', '5869', 'U']

SOLUTION: 11633

PROBLEM: ['w', '1335', 'G', 'h', '6729', '1999', 'u', 'I', 'r', 'm', '4757', 'W', '3715', '701', '1999']

SOLUTION: 21235

PROBLEM: ['Y', '3143', '3627', '1177', '4919', '5075', 'L', 'P', '1471', '8145', 'Z', 'r', '1535', 'D', '7603', '1523']

SOLUTION:
38218