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: ['4401', 'p', 'V', 'l', 'H', '7329', 's', '4717', 'l', '1773', '67', '179', 'l', '6991', 'a', '9377']

SOLUTION: 34834

PROBLEM: ['3557', '3345', '307', '9791', '1897', 'O']

SOLUTION: 18897

PROBLEM: ['H', 'U', '5379', 'd', '2373', '6631', 'L', '3395', '3137', '5453', 'Q', 'w', 'y', '8273', '9763', 'e']

SOLUTION:
44404