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: ['h', 'a', '1645', '2391', '759', '519', '3331', '2831', '3427', '9893', 'u', 'J', '7391', '8379', 'V']

SOLUTION: 40566

PROBLEM: ['5715', 'r', 'R']

SOLUTION: 5715

PROBLEM: ['7959', '1345', '4605', '6453', 'Q']

SOLUTION:
20362