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: ['K', '479', 'u', '3489', 'o', '9589', '7153', '7649', '123', 'a', 'A', '3951', '847', 'N', 'R', '947', '9243', 'G', 'a']
Example Output: 43470

Example Input: ['V', 'h', '5549', 'K', 's', '8337', 'Y', '497', 'z', 'T', '4467', '6333', 'M', '1573', 'y', 'O', '5499', 's', 't', '6205']
Example Output: 38460

Example Input: ['4367', '2145', '7107', '8055', '107', 'i', 'T', '6925']
Example Output:
28706