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', '4119', 'I', '475', 'd', 'L', '909', 'F', 'V', '775', 'k', 'A', '9411', '8383', 'W', '1521', 'z', 'j', '7057', 'I']