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: ['7959', '1345', '4605', '6453', 'Q']
Example Output: 20362

Example Input: ['r', 'B', '8791', '3165', 'n', 'm']
Example Output: 11956

Example Input: ['d', 'S', 'D', '8085', '2265', '6109', '1255', 'C', 'u', 'M', '8411', '4063', '2505', '1935', '5523', '1777', 'b']
Example Output:
41928