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.
--------
Question: ['v', 'a', 'O', 'S', 'r', 'T', 'r', 'K', 'K', '7781', '1749']

Answer: 9530


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

Answer: 29725


Question: ['7793', 'U', 't', 'a', 'c', '1865', '5217', '4299', 'z', '3369']

Answer:
22543