router OSPooF...

no router OSPF 0...

a router cannot have a process id of  0
area 0 - good; process id 0 -  HULK SMASH...

good router process-id:

router ospf 1
 log-adjacency-changes
 network 1.1.1.1 0.0.0.0 area 0
 network 10.0.20.0 0.0.0.255 area 0
 network 10.0.30.0 0.0.0.255 area 0
 network 192.168.1.0 0.0.0.255 area 0

bad router process id:

r2620_01(config)#router ospf 0
                                              ^
% Invalid input detected at '^' marker.

r2620_01(config)#

good router process-id

r2620_01(config)#router ospf ?
  <1-65535>  Process ID

r2620_01(config)#router ospf

can you say what is 2^16-1?