H O H hydrogen O oxygen hefty H O water O H O H O Rx H O C O O H C O O H C O O H H O H O wet feet H O first entry first entry second entry H C C H H C C H SIX,B r135 R246 RZ A,B,C,D,E,F SIX,B R135 R246 RZ A,B,C,D,E,F Z A B x C D,E,F SIX,B r135 R246 RZ A,B,C,D,E,F