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]: ['q', '867', 'e', 'z']
[EX A]: 867

[EX Q]: ['2485', 'Q', 'G', '5533', 'Y', '21', 'D', 'S']
[EX A]: 8039

[EX Q]: ['c', '7885', '1319', 's', 'L', '4193', 'x', 'N']
[EX A]:
13397