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.

Example input: ['238', 'h', '92', 'U', '2799']
Example output: 3129
Example explanation: Here, the numbers in the input list are '238', '92' and '2799', hence their sum (238+92+2799) is 3129.
Q: ['c', '6707', '97', '7909', '9905', 'A', '3153', 'b', 'Y', 'n']
A:
27771