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.

['901', 'X', 'W', 'D', 'm', 'M', '59', '4855', '6523', 'R', '9781', '8271', '4449', '2221', '8391']
45451

['2097', '7815', 'f', '1705', '7553', 'C', 'n', '7091', '1253', 'z', '9229', 'H', 'N', '6481', 'H', 'M', 'G', '4527', '8537']
56288

['7047', 'R', '4337', 'j', '1267', '9325', 'I', 'O']

21976