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]: ['6577', 'Q', '6865', '7671', 'N']
[A]: 21113


[Q]: ['U', '5607', 'Q', 'j', 'I', '3745', '3031']
[A]: 12383


[Q]: ['s', 'H', 't', 'w', '1667', '4165', 'a', 'N', 'I', '1391', '1349', '1897', 'W', '8353']
[A]:
18822