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: ['x', '1887', 'E', '3995', '5677', '2749', '9951']

SOLUTION: 24259

PROBLEM: ['y', 'p', '3553', '2155', 'b', 'R', 'j', 'V', 'U']

SOLUTION: 5708

PROBLEM: ['t', '5445', '8847', '6421', 't', '157', 'D', '6083', 'L', '187', 'z', 'i', '6547', '2161', '6331', '3343', '7283', '5691', 'k']

SOLUTION:
58496