Programming :: Shutdown Multiple Computers Via SSH (Try Different Passwords)

I'm trying to write a mass reboot script in the event of a power outage (servers go to UPS for some 15 minutes or so and shutdown uncleanly). What I have is a set of 6 common passwords which will be prompted for per ssh connection, is there any way I can cycle through this password list

Code:
#below is an example of how this is constructed, IP's are used instead of hostnames due to the possibility of a DNS server being offline.
SERVERSRM1="1 2 3"
SERVERSRM2="110 120 130"
For i in $SERVERSRM1; do ssh -n root@192.168.0.$i "hostname && shutdown -y -i5 -g0"; done;'
for i in $SERVERSRM2; do ssh -n root@192.168.0.$i "hostname && shutdown -y -i5 -g0"; done;'
Each time the code is executed I'm prompted for a password (it's always one of 6 passwords). It would be quicker to have the passwords be cycled through.

I realise this is basic code at the moment but it will eventually allow for a specific set of computers to be shut down based on what power supply they're using. Authorized keys not really an option given the scale of computers (some 300 or so).