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: ['u', 'B', '2509', 'U', 'R', '7497', '1897', '8697', 't', 'W', '1021', '7937', 'F', 'g', '6901', 'I', '2957']

Answer: 39416


Question: ['u', 'i', 'z', 't', '9617', 'd', '3255', 'w', 'S', '3041', '7451']

Answer: 23364


Question: ['O', 'E', 'b', '8935', '4165', '1409', '4421', 'C']

Answer:
18930