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]: ['z', 'E', 'u', '4437', '7767']
[EX A]: 12204

[EX Q]: ['3683', 'U', 'x', '313', 'n', '3837', '3299', '2081', '2773', 'r', 'O', '257', '6647', '585', 'o']
[EX A]: 23475

[EX Q]: ['W', 'B', 'C', 'D']
[EX A]:
0