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: ['k', 'a']

SOLUTION: 0

PROBLEM: ['A', 'S', 'c', 'I', 'M', 'P', '8739', '879', '1401', '3941', '4061', 'q', 'P', '2805', '4473']

SOLUTION: 26299

PROBLEM: ['O', 'l', 'X', 'N', '1149', '4121', '95', '6801', 'c', 'Q', '901']

SOLUTION:
13067