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:       Open you suitcase , please .  
 Person2:OK.Here you are .  
 Person1:        Do you have anything to declare ?  
 Person2:No , I don't .  
 Person1:        Any cigarette , liquor ?  
 Person2:Yes , I have two cartons of cigarettes , one bottle of whisky .  
 Person1:        What's this white powder ? Are they drugs ?  
 Person2:No , this is the medicine for the stomach .  
 Person1:        May I open one of these ? Let me taste it .  
 Person2:Yes , sir.Go ahead.Here you are . 

formal