Definition: You are given a conversation between two people. 'Person1:' and 'Person2:' are used to separate their respective dialogues. You are required to assign a label 'formal' if there is an absence of emotion and a presence of questions anywhere within the conversation. If such pattern is not found assign the label 'informal'.
Input:  Person1:       Do you think we should travel by bus or by train ? 
 Person2:It ’ s a difficult choice . The train is a litter faster , but much more expensive . 
 Person1:        We could face delays if we travel by bus , thanks to traffic jams . 
 Person2:Buses are more cramped and you can ’ t walk around . 
 Person1:        That ’ s true , but I feel that I see more when I travel by bus . 
 Person2:Really ? I think you see more traveling by train . 
 Person1:        So , which form of transport do you prefer to use ? 
 Person2:I prefer going by train , ever though it costs more . 
 Person1:        Ok them . We ’ ll go by train . I ’ m sure we ’ ll have a good journey . Shall we go to the station and buy the tickets ? 
 Person2:The train aren ’ t usually full . We can get them on the day we travel . We should buy return ticket because they are much cheaper than getting two singles . 
 Person1:        We should take a packed lunch on the journey . The food they sell on the trains is always expensive . 

formal