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:       I am not convinced by your explanation . Could you explain it ?  
 Person2:Sorry , I really can't do that . There's little time left for us .  
 Person1:        I can't accept your excuse . It's five o'clock .  
 Person2:But I have an appointment with Ann .  
 Person1:        Ok , sounds good . But I think it's your trick . 

informal