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', '7537', 'e', 'L', 'z', '4965', '1077', '7267', '1167', '2205', 'Z', 's', 'j', '1461', '9411', '2655', '4915', '1283', '7737']