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.
['4201', '4351', 'O', 'P', 'E', 'R', 'D', 'e', '9161', 'W', '3775', 'o', '3433', 'q', 'a', '5011', '5717']