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:       Where are you going for your holidays , Charles ?  
 Person2:To Australia . I'm going to visit my uncle in Brisbane for three weeks .  
 Person1:        Good gracious ! You certainly are lucky . How are you going there ?  
 Person2:By air , of course . It takes over two weeks to go by sea .  
 Person1:        I once went to Singapore by air . It was very exciting-but never again .  
 Person2:Why ? Did you feel frightened ?  
 Person1:        For a short time . One of the engines caught fire .  
 Person2:What did the pilot do ?  
 Person1:        He put it out and flew back to the airport . Then he asked the people at the airport where the emergency runway was .  
 Person2:Did you land safely ?  
 Person1:        Yes , we did . But I shall never fly again . 

formal