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]: ['B', 'u', '9227', 'b', '8767']
[A]: 17994


[Q]: ['2175', '4539', 'L', 'T', 'q', '2407', 'F', 'V', 'b', '9475', '2279', '4469', '6231']
[A]:
31575