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.
['V', '2285', '3553', 's', 'i', '6875', '4041', '2789', 'X', 'I', '4887', '9011', '8651', '4087', 'X', '4507', '2649', 'e', '2647']