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: ['Q', '8317', '8989']

Answer: 17306


Question: ['q', 'N', 'y', '7859', 'u', '2861', '4151', 'Q', 'x']

Answer: 14871


Question: ['U', '535', '5725', '5413', '4093', 'b', '8623']

Answer:
24389