Detailed 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.
Q: ['5721', '2165', 'P', 'n', '3925', '6069', 'B', 'Z', 'W', 'x', 'F', '4189', 'x', '3621', 'G', 'D']
A:
25690