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: ['5331', 'f', '2865', '6019', 'U', 'm', 'g', 'n', 'Y', 'A']

Answer: 14215


Question: ['2013', 'S', 's', '9353', 'b', 'u', '6687', '5429', '3545', '7269']

Answer: 34296


Question: ['2571', 'i', 'L']

Answer:
2571