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.

['9403', 'u', '4159', 'w', '3467']
17029

['U', '5607', 'Q', 'j', 'I', '3745', '3031']
12383

['V', '5967', '1501', '845']

8313