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: ['s', 'd', 't', '8235', '2279', '7477', '3029', '4377', '9153', '4309', '2295', '407']

SOLUTION: 41561

PROBLEM: ['6161', 'p', '2839', 'c', '5905', '1729', 'j', '5901', '3013', 'e']

SOLUTION: 25548

PROBLEM: ['4209', 'v', 'f', '7509', 'r']

SOLUTION:
11718