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

['S', 'W', '2171', '6405', 'h', 'C', '1597', '7109', 'Q', 'p', '2747', 't', 'J', 'q', '1883', 'v', 'O']
21912

['m', '5669', '8931', 'C', 'O', 'X', 'l', '7049', 'K', 'i', '1379', 'j']

23028