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:       Mary , would you like to get something to eat with me ?  
 Person2:OK . When ?  
 Person1:        At 10 o'clock .  
 Person2:10 in the morning ?  
 Person1:        No , at night .  
 Person2:Sorry , that's too late . I usually go to bed around 10:00 PM .  
 Person1:        OK , how about 1:30 PM ?  
 Person2:No , that's too early . I'll still be at work then .  
 Person1:        How about 5:00 PM ?  
 Person2:That's fine .  
 Person1:        OK , see you then .  
 Person2:Alright . Bye . 

informal