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.
['q', '9203', 'x', '79', 'B', 'J', '9531', 'D', '8791', '8111', '3365', 'e', '7481', '8531', '8775', '8047', '693', '8105']