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.
['E', 'Z', 'o', '5527', '6873', '7449', 'S', '3467', '3019', 'k', 'Q', 'p', '5905', 'j', '9699', '1821', '249', 'm']