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.

['7459', '491', '7823', '6965', 'H', '109', 'R', 't', '3959', '2821', 'R', '2807', 'o', 'v', '1305', 'a', '1411', 'r', '3669']
38819

['q', '6631', 'b', '4207', '7523', '9853', '9203', 'P', '5029', 'b', '2319', '4717', '2485']
51967

['6967', 's']

6967