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.

['8821', '7221']
16042

['s', 'd', 't', '8235', '2279', '7477', '3029', '4377', '9153', '4309', '2295', '407']
41561

['g', 'E', 't', 'W', 'k', 'i', '4923', 'S', 'M', 'N', 'O', '461', '7653', '7855']

20892