path2 fixed sql query

sql/path2.sql

 
 WITH path2(a,b) AS (
-	SELECT p1.a, p2.b from par p1 JOIN par p2 ON p1.b = p2.a
+	SELECT DISTINCT p1.a, p2.b from par p1 JOIN par p2 ON p1.b = p2.a
 ) SELECT Count(*) FROM path2;