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:       How much does it cost to hire a motorbike ?  
 Person2:For 3 days $ 300 , for 7 days $ 600 .  
 Person1:        Good . I think I'll hire one for 7 days .  
 Person2:Okay . I'll write up the paperwork . 

formal