--- a/src/rps_rules.erl	Mon Mar 03 22:17:13 2014 +0900
+++ b/src/rps_rules.erl	Mon Mar 03 22:17:50 2014 +0900
@@ -2,13 +2,19 @@
 -export([parse/1, winning_hand/2]).
 -include("rps_rules.hrl").
 
+add_unique(Elem, List) ->
+    case lists:member(Elem, List) of
+        true -> List;
+        false -> [Elem|List]
+    end.
+
 parse(Text) ->
     Tokens = lists:map(fun list_to_atom/1, string:tokens(Text, " ")),
     parse(Tokens, #ruleinfo{}).
 
 parse([V1,Label,V2|T], #ruleinfo{hands=Hands, beats=Beats, loses=Loses, why=Why}) ->
     Acc = #ruleinfo{
-        hands=[V1|Hands],
+        hands=add_unique(V1, Hands),
         beats=dict:append(V1, V2, Beats),
         loses=dict:append(V2, V1, Loses),
         why=dict:store({V1, V2}, Label, Why)},