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've never seen a machine like this before and need some help .  
 Person2:Sure , no problem . What are you trying to get ?  
 Person1:        I want to buy a drink .  
 Person2:OK . This machine needs you to use that change machine first to get correct change .  
 Person1:        I've got the correct change already .  
 Person2:First you put your money in the dollar slot or the coin slot . The dollars have to be smooth .  
 Person1:        OK , what next ?  
 Person2:Just know that sometimes the money doesn't go in perfectly the first time and you have to try again .  
 Person1:        OK , next ?  
 Person2:Choose what you want and push the button . Sometimes it takes a couple of tries .  
 Person1:        I agree with you .  
 Person2:Hope that works for you ! 

formal