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:       the dinner was really good . It knocked my socks off . 
 Person2:that's very kind of you to say so . Let's try some after-dinner wines . 
 Person1:        great . Sweet wines are my favorite . They always make a great finish to a decisions meal . 
 Person2:do you prefer brandy or ports . 
 Person1:        port , please . 
 Person2:excellent choice . I love its smooth flavor . 
 Person1:        the port is exquisite . It must have spent years aging in barrels . Am I right ? 
 Person2:yes . You always have a good nose for wines . 
 Person1:        next time we are about to dinner we should try some Canadian ice wine . 
 Person2:oh , what's that ? 
 Person1:        it's made from naturally frozen grapes . 
 Person2:why not ? It sounds great . 
 Person1:        oh , here's to your health . 
 Person2:thanks . Cheers . 
 Person1:        cheers . 

informal