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.
['7607', 'I', '1427', '8463', '7487', 'H', '953', 'B', 'y', 'V', 'd', '4083', 'V', 'm', 'y', '9155', '2655', '8841', 'L', 'c']