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: ['901', 'X', 'W', 'D', 'm', 'M', '59', '4855', '6523', 'R', '9781', '8271', '4449', '2221', '8391']

SOLUTION: 45451

PROBLEM: ['x', '9895', 'r', 'H', 'C']

SOLUTION: 9895

PROBLEM: ['l', 'q', '6241', 'B', 'Y', '5545', '1731', '4919', 'O', '627', '4645', 'J', '2729']

SOLUTION:
26437