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.

['3839', 'D', '4741', 'L']
8580

['D', '1259', '8927', '3345', '553', '7209', '2507', 'l', 'o', '7317', '1227', '6749', 'S', '3171', 'I', '197', '9577', 'j', 'Q']
52038

['Y', '9155', 'E', '4169', '6079', 'r', '8895', '6021', '6513', '9031', '6905', '129', 'z', '2043', '3501', '2319', 'O']

64760