Fix rank computation.

words.py

@@ -68,15 +68,15 @@ while Q:
     db.commit()
 
     r = db.execute('''
-        select q.word, q.rank
-        from words q
+        select q.word, q.rank, z.rank
+        from words q, words z
         where not exists (
             select *
             from combos c
             where c.x = q.word and c.y = ?
-        )
-    ''', (z,))
-    for q, q_rank in r.fetchall():
+        ) and z.word = ?
+    ''', (z, z))
+    for q, q_rank, z_rank in r.fetchall():
         Q.add(((z, z_rank), (q, q_rank)))
 
     time.sleep(5)