Hello, I'm wondering if there are any tricks to quickly determine the parity of the weight of a binary number, i.e., whether it's even or odd. I'm not interested at all in the actual weight of the number, but in the parity of it. I know that if say x = a XOR b, then x has odd weight iff exactly one of a, b, has odd weight. But would you have come across a good algorithm for this problem before? The web seems full of the actual Hamming weight problem, but haven't noticed anything special about this other case. Thanks a lot guys.