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: ['L', 'w', '2783', '6993', 'd', '9173']
Example Output: 18949

Example Input: ['w', 'I', 't', '813', 'K', '5785']
Example Output: 6598

Example Input: ['7563', 'h', 'u', 'Z', '9913', '8925', '5747', 'h', '3375', 'b', 'K']
Example Output:
35523