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.

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

[EX Q]: ['v', '3135', 'J', 'm', 'a']
[EX A]: 3135

[EX Q]: ['D', '6381']
[EX A]:
6381