Instructions:
Given: Some number of coins, all of which have equal weight
except for one. It is not known at the outset whether the odd coin is
heavier or lighter than the rest.
A balance which is able to compare the weights of two or more coins,
some placed on the left tray and some on the right tray. The balance
will either rotate clockwise, rotate counterclockwise, or not rotate
at all depending on whether the right tray coins are lighter, heavier,
or weighs the same as the left tray coins.
A number k.
Find: the odd coin in a number of weighings that is no greater
than k.
