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]: ['u', 'B', '2509', 'U', 'R', '7497', '1897', '8697', 't', 'W', '1021', '7937', 'F', 'g', '6901', 'I', '2957']
[A]: 39416


[Q]: ['N', '1337', 'C', 'T', '863', 'j', '2369', 'P', 'A', 'x', '5725', '2333', 'Q', '9149', 'Q', '8529', 'N']
[A]: 30305


[Q]: ['O', 'O', '7663', '8491', '1345', 'N', 'N']
[A]:
17499