Vikings tavern

Drinks!!! Drinks!!! A horde of mighty Vikings invade your tavern! They do not want to use your bathroom… their only goal is to drink your entire stock of beer! Quench their thirst before they get impatient. Send them beers and retrieve the glasses when they finish. Beware: Some Vikings are thirstier than others. With all these beers, there will be a long line for the bathroom, for sure! Your tavern has 4 large tables Many Vikings are waiting for their beers at the tables You must not deliver beers to an empty table