0 <-> cp
cp <-> ca
ca <-> dho
dho <-> oro
oro <-> omp
omp <-> ump
ump <-> udp
udp <-> utp
utp <-> 0
utp <-> ctp
ctp <-> 0
cp <-> 0
ca <-> 0
dho <-> 0
oro <-> 0
omp <-> 0
ump <-> 0
udp <-> 0
utp <-> 0
ctp <-> 0