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: ['5199', 'h', 'T', 'T', 'l', '1661', 'p']

SOLUTION: 6860

PROBLEM: ['6787', 'W', 'I', '4929', 'j', 'I', '3487', 'F', '3927', 'Q', 's', 'X', '9939', 'n']

SOLUTION: 29069

PROBLEM: ['w', 'i', 'Y', '7011', '999', '2551', '9493', 'j', 'F', 'a', '5165', 'f', 'K', '8475', 'C', 'd', '3407', '9253', 'U']

SOLUTION:
46354