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: ['t', 'v', 'B', 'Y']

Answer: 0


Question: ['R', 'J', 'z', 'o', '1121', '7247', '8987', 'u']

Answer: 17355


Question: ['4117', 'R', 'n', '8353', 'u', 'w']

Answer:
12470