Instructions: 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.
Input: ['1907', '9001', '2117', 'a', 'z', '5887', '7169', '809', 'N', 'T', '1541', 'Q', 'a', '371', 'T']
Output:
28802