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.

['z', '2783', 'Y', 'm', 'b', '9107', '2115', '5395', '3433', 'k', '2229', '7663', '5635', '3201', 'b', 't', 'I']
41561