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:       Excuse me , sir . Could you spare a minute ?  
 Person2:Uh , yes .  
 Person1:        Do you go to work by train every day .  
 Person2:Yes . I commute five days a week by train .  
 Person1:        And would you mind telling us what you think of the rail service ?  
 Person2:It ’ s really very good .  
 Person1:        Why do you say that ?  
 Person2:Well , trains are frequent and come on time .  
 Person1:        Which train do you catch in the evening ?  
 Person2:I usually take the five thirty home .  
 Person1:        And can you get a seat ?  
 Person2:No , I usually have to stand .  
 Person1:        Would you agree that the service is fast ?  
 Person2:Yes , it ’ s reasonably fast but it certainly isn ’ t cheap . Fares have gone up 25 present . 

formal