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.

['L', 'w', '2783', '6993', 'd', '9173']
18949

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

['5951', 'w', '7771', 'i', '8207']

21929