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.
['c', 'w', 'u', 'J', '7197', '1649', 'u', '7549', '5531', '5575', '9795', '6561', '6111', '3365', '6909', 'f', 'k', 'T', 'p']