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.
['I', 'W', 'F', 'M', 'q', '6311', 'M', 't', '6251', 'd', '9015', '8717', 'N', '6947', 'f', '6763', 'Y', 'v', 'h', 'I']