In a round robin tournament with N teams,
every 2 teams play in a head-to-head
match. Points are awarded as follows: 3
points for a win, 1 points for a tie and 0
points for a loss. What is the smallest
value of N, such that it is possible for all
the teams to have the same number of
points, but for (at least) two teams to win
a different number of matches?