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: ['1815', 'U', '869', 's', '1847', 'C', '2711', 'S', 'i', '7949', '4477', '5093', 'D', '8661', '3835', '4087', '73', 'V', '3149', 's']

SOLUTION: 44566

PROBLEM: ['83', 'k', 'p', 'o', 'b', '7819', '2089', '4141', 'c', 's', '6045', '6783', 'J', 'B', 'x', 'O', 'X', '9693']

SOLUTION: 36653

PROBLEM: ['3555', 'n', 'f', 's', '4987', '7777', '1583', '7841', '6973', '2425', '4417', '4089', '4749', 'j', 'N', '6933']

SOLUTION:
55329