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: ['543', '8351', 'I', 'M', '6647', '731', 'b', 'r', 'l', '3935', 'k', 'z', 'v', '2131', '7781', 'X', '9419', '5013', 'F']
Example Output: 44551

Example Input: ['433', 'y', '2015', '5997', 'X', 'u', '9321', '8037', 'N', 'Z', 'E', '4645', '627', '6595', '7679']
Example Output: 45349

Example Input: ['o', 'T', '731', 'r', '6403', 'U', '2173', 'w', 'C', 't', '2109', 'F', '4395', 't', 's', '235', 'W', '2853', 'w']
Example Output:
18899