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: ['5095', '8235', '4901', 's', '4177', '3077', 'l']

SOLUTION: 25485

PROBLEM: ['l', '1329', 'P', 'H', '3133', 'L', 'P', '7999', 'x', '8081', '6657']

SOLUTION:
27199