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: ['887', '8133', 'X', '2253', '8461', 'I', '5425', 'Z', 'z', 'r']

SOLUTION: 25159

PROBLEM: ['M', 'F', '4477', '1565', '4407', 'r', 'v', '7237', '83', '5243', 'O', 'z', 'W', '7703', 'Q', 'i', '9657', 'n']

SOLUTION: 40372

PROBLEM: ['1905', 't']

SOLUTION:
1905