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:       Hello , Mary . Nice day , isn't it ? 
 Person2:Yes , what a wonderful day ! The sky has cleared up in the end . 
 Person1:        I do feel like an outdoor exercise . After all , we haven't had such a beautiful day for a long time . 
 Person2:How about taking a walk in the park ? 
 Person1:        OK . It's delightful to have a walk in the park with the air so fresh . 
 Person2:( After they entering the park ) Great , it's so quiet here . We have the park to ourselves , only you and me . 
 Person1:        Are you kidding ? Don't you see many people over there ? Just on your right . 
 Person2:Oh , I see them . Beautiful weather should be shared by all the people . 
 Person1:        Ah , you changed so fast . 

informal