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.

['3839', 'D', '4741', 'L']
8580

['d', '5571', '6455', '4287', 'I', 'U', 'M', '8303', '8893']
33509

['h', '9539', '3373']

12912