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: ['6255', '8457', 'V', 'z', '4405', 'X', '9267', '5329', 'I']
Example Output: 33713

Example Input: ['9869', '7701', 'H', 'o', 'v', '1431', 'O', 'L']
Example Output: 19001

Example Input: ['3873', 'D', '6749', 'P', '4805', '4379', 'T', '8819', '8275', 'A', '4113', '9345', 'O', 'M', 'L', '5789', 'u', '557', 'C']
Example Output:
56704