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.

['Q', '6383', 'P', '8455', '3881', '5821', 'e', 'v', '1421', 'Q', '6377', '3157', '6407', 'q']
41902

['2787', 'z', '9351', '3339']
15477

['R', '3955', 'S', '4681']

8636