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.
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Question: ['4271', 'N', 'M', '5239', '7037', 'x', 'U', 's', '7107', '4163', 'f', '3607', '6155']

Answer: 37579


Question: ['R', '3361', 'c', 'S', 'g', '3829', '7347', '6633', 'e', '9227']

Answer: 30397


Question: ['4215', '7631', 'D', '6439', 'S', '2369', '4121', '9065']

Answer:
33840