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.
['V', '3149', 'g', 'u', 'i', '9025', '8417', 'O', 'V', 'H', '959', '3077', 'R', '4727', 'Y', 'W', '9861', '8329', '963', '8141']