The land of Euclidia has six remote towns, which we shall call A, B, C, D, E,
and F. Unfortunately, not all the towns
are connected by telephone lines.
Town A is connected to all the other
five towns, but Town B is connected to
only four. Town C, too, is connected
to four; whereas D, E, and F are each
connected to only three towns.
There is a line from Town D to
Town F. To what towns is Town E
connected?