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

SOLUTION: 34764

PROBLEM: ['M', '9933', '9861', 'f', 'N', 'R', '7625', 'p', 'T']

SOLUTION: 27419

PROBLEM: ['r', '5041', 'P', 'H', '8671', '6987', '6521', '1071', 'C', 'E', '2043', '9035', '9817', '3223', 'U', 'q', 'U', 'e']

SOLUTION:
52409