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: ['u', 'W', '1561', '9243', '4923', '9385']

SOLUTION: 25112

PROBLEM: ['P', '6299', '9655', 'l', '6317', '2139', '3347', 'l', '3095', '7363', '3115', '7529', 'R']

SOLUTION: 48859

PROBLEM: ['9767', '5631', 'T', '3565', '6027', '9953', '9073', '9907', '455', '2673', 'N']

SOLUTION:
57051