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: ['M', 'H', 'l', 'Y', '3811', '1953', '5869', 'U']

SOLUTION: 11633

PROBLEM: ['q', '867', 'e', 'z']

SOLUTION: 867

PROBLEM: ['9787', '1491', '4411', '5261', 'U', '9787', 'b']

SOLUTION:
30737