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.
['E', 'I', '8519', '4795', '8475', 'n', 'U', '4627', 't', '179', '3219', '685', '5409', 'C', '4073', '9313', '9113', 'T', 'A']