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.

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


[Q]: ['8669', '9115', '2573', '9261']
[A]: 29618


[Q]: ['D', 'R', '3905', '5921', 'Y', 'b', '991', 'g', 'z', 'f']
[A]:
10817