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:       May I speak to Mr . Thomas ?  
 Person2:Unfortunately , he has left for the day .  
 Person1:        I hate to trouble of you . But it is urgent . Please leave this message into him  
 Person2:I ’ ll make sure he gets the message . 

informal