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The machine is necessary. Although the spy is able to produce a Y number with the machine and the guard knows Y, if the guard doesn't know X he also doesn't kno
by ernestobad 16y ago
The machine is necessary. Although the spy is able to produce a Y number with the machine and the guard knows Y, if the guard doesn't know X he also doesn't know how to generate a Y number with the machine.
- brianpan 16y agoYeah, you have to make a leap that's not explained in the puzzle. An intermediate machine or some other method has to be used to keep the secret a secret, yet the answer can be "public".