Sasha likes programming. Once, during a very long contest, Sasha decided that he was a bit tired and needed to relax. So he did. But since Sasha isn't an ordinary guy, he prefers to relax unusually. During leisure time Sasha likes to upsolve unsolved problems because upsolving is very useful.Sasha likes programming. Once, during a very lo
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Sasha and a Bit of Relax（前缀异或和+二维数组+思维）
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