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: ['7067', 'E', 'C', '1879', 'Z', 'u', 't', '2053', '6769', 'r', '5207', '7009', 'H', '5587', 'i', 'M', '1357', 'A']

SOLUTION: 36928

PROBLEM: ['s', 'M', 'U', '5383']

SOLUTION: 5383

PROBLEM: ['3629', '8785', '9537', '8479', '3523', 'c', 'C', '5093', '2405', 'y', '1145', '8987', 'f']

SOLUTION:
51583