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: ['y', 'R', 'b', 'v', 'm', 'H', '9903', '8689', 'D', '1023', 'a', '233', '1833', 'o', 'n', 'm', '5531']
Example Output: 27212

Example Input: ['Q', '2271', '1803', '2363']
Example Output: 6437

Example Input: ['p', '7851', 'F', '3471']
Example Output:
11322