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', 'I', 'i', 's', '3229', 'r', 'j', 'T', '4263', '7627', '5459', '8717', 'M', 'l', 'r', '867', '6901', '5951', '1893', '6607']