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.

['g', 'A', 'r', '539', '5459', '2725', '7447', '3693', '1757', 'r', 'W', '5949', '4569', '5153', '3985', 'Q', '505', 'M', '8989']
50770

['6941', 'I', 'j', '6135', '6525', '7853', '5607']
33061

['2683', '5149', 'l', 'Z', 'n', '3627', 'l', '8873', '2915', 'c', 'C', '5447']

28694