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.

['C', 'v', '1353', 'e', 'x', 'A', 'D', '1243', '477', 'z', '3483', '5213', 'k', 'm', 'n']
11769

['P', '6299', '9655', 'l', '6317', '2139', '3347', 'l', '3095', '7363', '3115', '7529', 'R']
48859

['8539', 'i', 'B', 'c', 'p', 'O', 'Q', 'B', 'r', '2975', '8423', '8879', 'g']

28816