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

Example Input: ['5499', '39', 'Q', 'b', 'W', '7155', '2515']
Example Output: 15208

Example Input: ['e', '6633', '131', '7459', '3733']
Example Output:
17956