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: ['K', '4403', 'a', '3881', '4139', 'w', '1861', 'G']

Answer: 14284


Question: ['M', '6989', 'I', 'w', '3591', '3067', '3883', 'C', '6049', '5723', 'j', '5989', 'C', 'R', '475', '7779', '671']

Answer: 44216


Question: ['8201', '8039', '7279', 'j', 's', 'i', '4053', 'u']

Answer:
27572