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', '9787', '7533', '9489', 'C', '1753', '5121', '1405', '9267', '4815', 's', '5887']

Answer: 55057


Question: ['7465', 'G', '105', 'A', '3987', 'O', '7385', 'C', '8957']

Answer: 27899


Question: ['M', 'G', '8159']

Answer:
8159