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class Solution {
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  public int[] singleNumber(int[] nums) {
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    if (nums == null || nums.length < 2 || nums.length % 2 != 0) {
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      throw new IllegalArgumentException("Invalid Input");
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    }
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    int aXORb = 0;
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    for (int n : nums) {
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      aXORb ^= n;
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    }
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    int rightSetBit = aXORb & -aXORb;
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    int a = 0;
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    for (int n : nums) {
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      if ((n & rightSetBit) != 0) {
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        a ^= n;
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      }
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    }
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    return new int[] {a, aXORb ^ a};
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  }
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}