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{ 3, 4, 21, 28, 29 }
{ 1, 2 }
{ 6, 7, 8, 22 }
{ 5, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 25 }
{ 14, 20, 23, 24, 26, 27, 30, 31 }
{ }
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