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: ['8109', '5635', 'u', 'M', '1009']

SOLUTION: 14753

PROBLEM: ['L', 'i', '9225', 'w', '5365', '8077', '2733', 'W', '8493', 'B']

SOLUTION: 33893

PROBLEM: ['5419', '8073', '3449', 'z', '8337', 'Y', 't', 'j', 'y', '5295', '4309', '9885', '9205', 'j', 'k', '6461', '505', 'b', '8437']

SOLUTION:
69375