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.

['Z', '4157', '5185', 'U', 'i', '1115', 'A', '7427', '3313', 'S']
21197

['G', 'e', 'R', '4427', '3401', '3065', 'I', '2781', '6829', '5261']
25764

['n', '1849', 'I', '8799', '6061', '9905', '4433', '3267', 'j', 'k', '2265', 'k', '4535', '8505', '6759']

56378