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.
['6233', '4765', 'r', '2059', '3557', '5165', 'w', '2077', '6251', 'E', '3549', '8011', 'n', '173', '389', '5627', 's', '5583', 'b', 'Q']