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:       Hi Amy , you look very happy .  
 Person2:Yes , I'm very pleased . I've just got two tickets to see the Olympic opening ceremony .  
 Person1:        Wow . You must be very excited .  
 Person2:I certainly am . I would have been very disappointed if I hadn ’ t got them .  
 Person1:        Shall we go to a restaurant to celebrate ?  
 Person2:What a good idea . I'm quite hungry .  
 Person1:        Me too . I feel very thirsty as well .  
 Person2:Let ’ s go then . 

informal