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.

['B', '9189', '3691', '2869', '1525', 'd', 'H', 'P', '8613', 'b', 'r', '5289', 'V', '6433', '8733', 'K', '8105', '1041', 'U', 'L']
55488

['D', 'P', '9951', '2897', 'V', 'C', 'B', 'H', 'c', 'h', '2843', 'a']
15691

['6707', 'q']

6707