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.

['n', '6729', 'p', 'D', 'o', '1213', 'e', '6951', '2341', '9997', 'e', 'M', 'x', 'R']
27231

['z', '3199', 'r', '849', 'C', 'v', '1931', 'M', 'Q', '4531', '579', 'x', '8997', '4663']
24749

['f', 'P', 'g', 'z']

0