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.
['k', 'o', 'X', '1513', 'T', '429', '8173', 'F', '8311', 'd', 'o', '7563', 'X', 'g', 'a', '8669', 'M', 'B', '5697', 'i']