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]: ['8609', '8045', '2517', '3821', 'x', '3895', 't']
[EX A]: 26887

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

[EX Q]: ['6871', 'U', 'x']
[EX A]:
6871