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.
['c', '4403', '9407', '6861', '6021', '4099', '8257', '9497', '8433', 'J', 'e', '7501', 't', '2301', '9601', 'v', 'i', '9411']