The Four FreestylersOnce more I will do a picture to make it more understandable.
Four freestylers got captured by professionnal footballers who don't like freestyle. They say "you can't use this in a real football match", so
they decided to dig the freestylers in the ground exept for their heads. The fsers can absolutely not move, also they can't move or turn their
heads. Between freestyler A and freestyler B is a massive wall, so they can't see each other. Besides, all the freestylers know that each one
of them wears a hat. Two hats are white, two are black (they know this.) However, they do not know which freestyler wears which color.
To avoid that they will get killed by the pro footballers, one freestyler has to guess his own hat color. When he gets wrong, all the fsers will
get killed, so there is no second chance: he must be absolutely right. The four freestylers are not allowed to speak with each other, and they
get 10 minutes times to think it over. After a few minutes, one freestyler guesses the correct color of his hat, and all get free. Now the question:
Which freestyler knew the correct answer, and why was he absolutely right that it was correct?
Notice: every single piece of information is useful.