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', '1489', 'x', '6543', 'I', 'l', 'D', '6299', '1473', 'a', '7661', 'z', 'E', 'Z', 'U', '3671', '2873', 'e', 'p']

SOLUTION: 30009

PROBLEM: ['k', 'a']

SOLUTION: 0

PROBLEM: ['X', 'P', 'L', '5597', '4477', '2747', 'g', '3533', 'J', 'f', 'S', 'D']

SOLUTION:
16354