Godel wants to go from London to Gottingen, but in the midle of the way the road is branched in to two ways, To the left and to the right. He doesn't know what road should he take.
Fortunately (or should I say unfortunately) he meet 2 people. They are twins, named Romus and Romulus. The twins know about the road to Gottingen.
Godel only know that one of them is always lying, but the other is always says the truth. Godel doesn't know which one of them will lie or says the truth.
Romus knows about the Romulus character (liar or not) and Romulus also knows about Romus character.
What question should he ask to each of the twins in order to know the road to Gottingen?
Godel was given two chances : 1st is to ask Romus and then 2nd is to ask Romulus.
Each of them is asked by Godel in different places.
I'm sorry for my bad English.