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: ['I', '7815']

A: 7815
****
Q: ['M', 'H', 'l', 'Y', '3811', '1953', '5869', 'U']

A: 11633
****
Q: ['n', '3529', '6549', '1997', 'B', 'f', 'g', 'g', '6225', 'k', 'g', 'q', 'Z', 'd', 'a']

A:
18300
****