mhc2 nhc2o ohc2o9 phc2 qhc2o
b8c2o c8c2o9 d8c2 e8c2o f8c2o9
0yd2o9 1yd2 2yd2o 3yd2o9 4yd2
ppe2 qpe2o rpe2o9 spe2 tpe2o
egf2o fgf2o9 ggf2 hgf2o igf2o9