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: ['9211', '1889', '7371', '9649', 'b', 'y', 'q', 'a', 'i', '1137', '3291', '8625']

SOLUTION: 41173

PROBLEM: ['57', '9977', '2657', 'p', '9573', '7745', '4755', 'U']

SOLUTION: 34764

PROBLEM: ['p', 'H', '1149', 'a', 'I', '1731', 'W', 'R', '4487', '2621', 'z']

SOLUTION:
9988