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.

[Q]: ['W', 'H', 'k', 'L', '2425']
[A]: 2425


[Q]: ['1671', 'H', '9271']
[A]: 10942


[Q]: ['3487', '3289', 'Q', '7955', '1329', 'U', '5429', '2381', 'K']
[A]:
23870