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.

['2729', 'W', 'i', '9073', '343', 'j', '2329', '9159', '4825']
28458

['r', '6537', '3001', '7879']
17417

['u', 'v', 'm', '3449', '7281', 'l', '7197', '7385']

25312