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]: ['F', 'z', '1159', '345']
[A]: 1504


[Q]: ['b', 'O', '7023', 'q', '2667', '681', 'C', '5707', '7125', 'q', 'Q', '1375', '8869', '6709']
[A]: 40156


[Q]: ['7165', 'o', 'c', '7937', '2343', 'X', 'Z', 'u', 'L', '4429', 'e', 'w']
[A]:
21874