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: ['s', '407', '7983', '1523', '8983', '9841', 'p', 'y', 'N', '7633', 'T', '4177', 'Z', 'Y', '3223', '7125', '2601', '7467', '3039']

SOLUTION: 64002

PROBLEM: ['6941', 'I', 'j', '6135', '6525', '7853', '5607']

SOLUTION: 33061

PROBLEM: ['I', 'z', 'R', 'm', '4201', 'w', 'c', '1093', '8171', '7759', 'n', 'c', 'R']

SOLUTION:
21224