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', '4991', '7289', '4355', 'I', '8415', '5175', '5329', 'G', 'a', '7193', 't', '8821', 'j', '7239', '405', 'y', 'O', '9881', 'w']

Answer: 69093


Question: ['6867', 'x', '8481', '5091', '979', 'a', 'S', 'i', 'd', '1591']

Answer: 23009


Question: ['X', '7175', 'n', '7659', '5579', 's']

Answer:
20413