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.

Ex Input:
['1391', '1719', '8547', 'x', 'a', 'j', '6395', 't', '3421', '6607', 'M', '1645', 'H', 'x', 't']

Ex Output:
29725


Ex Input:
['w', '1335', 'G', 'h', '6729', '1999', 'u', 'I', 'r', 'm', '4757', 'W', '3715', '701', '1999']

Ex Output:
21235


Ex Input:
['6387', '1615']

Ex Output:

8002