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.
['1463', '965', '1225', 'p', 'U', '7609', 'q', '3567', 'k', '9823', '8587', '9149', 'V', 'o', 'K', 'K', '2907', '5733', 'j']