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: ['U', '9593', '2079', '5959', 'T', '5849', 'w', 'b', '9743', '6689', 'k', 'J']

SOLUTION: 39912

PROBLEM: ['6867', 'x', '8481', '5091', '979', 'a', 'S', 'i', 'd', '1591']

SOLUTION: 23009

PROBLEM: ['7607', 's', '3511', '977', '5771', '9749', '7761', '3493', '6483', '5367', 'P']

SOLUTION:
50719