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: ['J', '5149', 'H', 'L', 'm', 'h', '3863', 'n', 'z']
Example Output: 9012

Example Input: ['D', '1259', '8927', '3345', '553', '7209', '2507', 'l', 'o', '7317', '1227', '6749', 'S', '3171', 'I', '197', '9577', 'j', 'Q']
Example Output: 52038

Example Input: ['7759', '5735', '3565', '1101', 'D', '4133', 'k', 'n', 'l', '7929', 'z', '7223', '2019', '9781', '3827', 'I', '4523']
Example Output:
57595