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: ['h', '6937', 'U', 'f', 'S', 'm', '9699', 'E', '4559', 'p', 'Z', 'o', '6409', 's', '4537', '5135', '6901', '6489', '5833', 'l']
Example Output: 56499

Example Input: ['6645', 'k', '4879', 'N', '113', 'L', 'x', '8365', 'v', 'A']
Example Output: 20002

Example Input: ['d', 'B', 'u', 'A', '5715', 'h', '1147', '7733', '8603']
Example Output:
23198