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.

['X', '989', 'U', '9551', '6385', 'Y', '1433', 'J', '1833', '685', 'u']
20876

['Z', 'w', 'M', '2233', '5275', '5277', 's', '971', '7085', '6259', 'V', 'E', '4923', '7365', 'c', 'd', 'c', 'U', 'P']
39388

['283', '3523']

3806