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.
['1037', 'h', 'V', '1871', '673', '6619', 'O', 'N', 'Y', 'V', '4913', '3775', '471', 'k', 'p', 'C', 'Z', '4303']