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:       Excuse me , do you know where the Post Office is ?  
 Person2:Yes , it's not very far from here . Follow this road until you get to the traffic lights . You will see a small restaurant at the corner .  
 Person1:        Is the restaurant on the right or on the left hand side of the road ?  
 Person2:It is on the right . But it is on the other side of the lights .  
 Person1:        OK . Do I turn on the lights or do I go straight ?  
 Person2:You go straight on at the lights , but just past the restaurant building there is a small road to your right .  
 Person1:        And do I take that road ?  
 Person2:Yes , you need to turn right and follow that road for about four minutes . You will see the Post Office on your left .  
 Person1:        Is there a Post Office sign on the building ?  
 Person2:Yes and it is quite a big building so you won't miss it . There is also a small supermarket next to it .  
 Person1:        Thank you very much .  
 Person2:You're welcome . 

informal