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]: ['E', 'X', 'C', 'v', '2803', 'g', 'b', '763']
[EX A]: 3566

[EX Q]: ['R', '3361', 'c', 'S', 'g', '3829', '7347', '6633', 'e', '9227']
[EX A]: 30397

[EX Q]: ['n', 'j', '5787', 'T', '3587', 'B', 'm', 't']
[EX A]:
9374