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: ['h', '2335', '2669', '6035', '9901', '7721', 's', '6181', 'C', 'l', 'x', '8275', '1103', 'S', '6447']
Example Output: 50667

Example Input: ['3013', '3955', 'f', '1183', '5111', '9509', '2351', '7087', 'f']
Example Output: 32209

Example Input: ['g', '6245', 'u', 'U']
Example Output:
6245