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: ['w', '7301', '9411', 'z', 'g', 'X', '1045', 'l', 'F', 'M', 'R', '7957', 'e', '5145']
Example Output: 30859

Example Input: ['C', '9973', 'b', '693', 'y', 'H', 'C', 'P', 'b', 'J', 'f', 'T', '2317', 'O', '5755', '8201', 'p', 'y', '8721', 'i']
Example Output: 35660

Example Input: ['F', 'z', '1159', '345']
Example Output:
1504