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.

['4749', '1169', '4273', 'X']
10191

['2975', '33', '2845', '4695', 'j', '607', 'e', 'z', '6339', '1899', 'q', 'O']
19393

['4271', 'N', 'M', '5239', '7037', 'x', 'U', 's', '7107', '4163', 'f', '3607', '6155']

37579