Problems from Waterloo Programming Contest 2004-09-25

	Submissions				Users
Name	Total	Acc.	Ratio	Fastest	Total	Acc.	Ratio	Difficulty
Antiarithmetic?	1538	279	18%	0.01	346	199	58%	7.2
Help!	1766	318	18%	0.00	243	175	72%	6.5
Test	82	42	51%	0.01	26	22	85%	5.7
Treequivalence	55	19	35%	0.00	22	18	82%	6.2