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: ['1875', '9833', 'i', '7493', 'J', 'P', 'z']

Answer: 19201


Question: ['1345', '2919']

Answer:
4264