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: ['2087', '8171', 'c', 'd', 'a', '5621', 'n']
Example Output: 15879

Example Input: ['1073', 'i', 'o', 'j', 'O', 'g', 'X', '3261', '5105', '4831', 'J']
Example Output: 14270

Example Input: ['h', 'n', '1955', '4077', 'X', 'N', '9241', 'T', '4073', 'F', '8485', '3709', '9609', 'S', 'Y', 'f', 'y']
Example Output:
41149