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.
['6195', 'd', 'h', '6725', '7199', 'H', 'Q', '9697', 'C', '5897', '841', 'k', 'q', '1787', 't', 'G', '3655', '5727', '7839', '8943']