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:       Would you like to go sightseeing tomorrow ?  
 Person2:Not a bad idea !  
 Person1:        What would you like to see in Beijing ?  
 Person2:Well , let me see . I'd like to go to the Great Wall , the Summer Palace , the Forbidden City and the Temple of Heaven .  
 Person1:        OK . I'll pick you up here tomorrow . 

informal