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]: ['507', 'P', '9697', 'u', '5057']
[EX A]: 15261

[EX Q]: ['29', 'N', '5061', '7191', 'z', '8367']
[EX A]: 20648

[EX Q]: ['4813', 'C', '4023', 'l', '6115', '4653', 'M', '5319']
[EX A]:
24923