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]: ['K', '479', 'u', '3489', 'o', '9589', '7153', '7649', '123', 'a', 'A', '3951', '847', 'N', 'R', '947', '9243', 'G', 'a']
[A]: 43470


[Q]: ['o', 'O', 'H', '7619', '6435', 'X', 'g', '1663']
[A]: 15717


[Q]: ['135', 'o', 'x', 'm', 'u', 'e', '4317']
[A]:
4452