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.
['A', 'C', 'a', '9195', 'B', '3305', 'H', '4361', 'u', 'w', 'a', 'o', 'Z', '9769', 'm', '2743', 'x', '3051', '5403']