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.

['z', '3199', 'r', '849', 'C', 'v', '1931', 'M', 'Q', '4531', '579', 'x', '8997', '4663']
24749

['6833', 'R', '7323', 'd', '3487', '8777', '9053', 'y', 'i', 'O', '467', 'b', '5969', 'D', 'B', 'r', '3073', 'i', 't', 'd']
44982

['I', '2877', '1707', '2405']

6989