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: ['N', 'V', 't', 'X', 't', 'M']
Example Output: 0

Example Input: ['8665', '6083', '9819', 'H', 'p', 'S', 'R', '4311', 'R', '7193']
Example Output: 36071

Example Input: ['81', 'n', '5887', 'Z', 'P', 'b', 'r', 'k', 't', 'l', '8399', 'Y', 'U', '2349', 'L']
Example Output:
16716