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: ['4201', '6445', '4009', 'q']

SOLUTION: 14655

PROBLEM: ['x', '1305', 'b', '8193']

SOLUTION: 9498

PROBLEM: ['u', 'B', '1023', '1969', 'F', 'w']

SOLUTION:
2992