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', '2271', '1803', '2363']
[EX A]: 6437

[EX Q]: ['211', '7561', '8725', '6139', 'I', '6585', '4231', 't', '2983', 'T', 'S', '9569', 'R', 'b', 'N', 'X', '9009']
[EX A]: 55013

[EX Q]: ['9825', '8147', '6829']
[EX A]:
24801