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]: ['5715', 'r', 'R']
[EX A]: 5715

[EX Q]: ['4425', 'x', '1959', 'C', 'c', 'D', 'M', '8317', 'q', 'x', '4277', 'N', 'z', 'I', '1921', 'o', 't']
[EX A]: 20899

[EX Q]: ['I', 'K', 'x', 'Z', 'j', 'l', '9537', 'D', '4057', '4493', '9133', '8047']
[EX A]:
35267