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.

['D', '1693', 'f', 'B', 'o', '3947', '8667', 'f', '6721', '4191', '79']
25298

['P', '6299', '9655', 'l', '6317', '2139', '3347', 'l', '3095', '7363', '3115', '7529', 'R']
48859

['i', '4313', '1543', '5599', 'f', 's', '3901']

15356