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]: ['Q', '2271', '1803', '2363']
[A]: 6437


[Q]: ['8683', 'p', '47', '8983', 'g', 'u']
[A]: 17713


[Q]: ['7589', 'I', '2555', 'D', '1619', '1917', '731', 'n', 'j', '1097']
[A]:
15508