It's Friday afternoon. You are waiting for your friend at Prague airport. You and your friend planned to spend a weekend in prague. Unfortunately, you looked for the flights so late that you were not able to book the same flight as every flight on Friday only had one seat remained. Weird,  right? But flight tickets are usually sold out quickly during "tourist season"... 

Eventually, you booked different flights: your friend are supposed to arrive three hours later than you do.