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: ['Y', '9053', 'N', '6921']

SOLUTION: 15974

PROBLEM: ['I', 'n', '3069', '477', 'F', 'k', '847', '6777', 'N', 'X', 'F', '1417', '9445', 'o', 'v', 'd', '2169', 'w']

SOLUTION: 24201

PROBLEM: ['A', 't', 'K', 'o', '7971', '2567', 'S', '379', 'd', 'e', 'K', '1919', '6869', '2917', 'G', '4147', 'j', '2063', '9737']

SOLUTION:
38569