y2nb
z2nbn
02nbno
12nb
22nbn
ntobn
otobno
ptob
qtobn
rtobno
ckpbno
dkpb
ekpbn
fkpbno
gkpb
1aqb
2aqbn
3aqbno
4aqb
5aqbn
q1qbn
r1qbno
s1qb
t1qbn
u1qbno