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.
['6131', '2437', 'q', '3527', 'c', 'j', 'j', '8103', 'c', '3855', 'k', 'p', '1923', '5121', 'j', 'G', '4293', 'P', 'V']