5si2o 4si2 3si2oh 2si2o 1si2

g2h2 f2h2oh e2h2o d2h2 c2h2oh

rbh2oh qbh2o pbh2 obh2oh nbh2o

2kg2o 1kg2 0kg2oh zkg2o ykg2

duf2 cuf2oh buf2o auf2 9tf2oh