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.

[EX Q]: ['3145', 'C', '7725', 'k', 'z']
[EX A]: 10870

[EX Q]: ['5573', '6221', 'C', '8649', '6603', 'q', '9403']
[EX A]: 36449

[EX Q]: ['6335', '2751', '5085', 'b', '1573', 'M', 'g', 'q', '875', 'x', '2489', '6141', '4961', '3133']
[EX A]:
33343