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 , is this the Guyon Travel Agency ?  
 Person2:Yes , sir . What can I do for you ?  
 Person1:        I want to travel to the ancient town in the south of China . Would you please tell me something about it ?  
 Person2:Sure . There's network of canals . And there are white walls , black tiles , small bridges , flowing rivers , flagstones roads , blue sky and white clouds . Few places have preserved the past like this place . Walking on the ancient road makes us back to our sense .  
 Person1:        Wonderful . That's just what I expect , where is my first place if I go there ?  
 Person2:Zhouzhuang .  
 Person1:        How long does the tour take ?  
 Person2:It's about two days .  
 Person1:        what's the cost ?  
 Person2:It's about 300 yuan .  
 Person1:        I know . Thank you very much .  
 Person2:That's all right . May you have a good trip !  
 Person1:        Thank you .  
 Person2:My pleasure . 

informal