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:       How was the party yesterday ?  
 Person2:Did you enjoy it ?  
 Person1:        Oh , don't talk to me about yesterday ! It was the most awful evening I've ever had .  
 Person2:Why ! what happened ?  
 Person1:        Well.John had promised to be my date , but he stood me up . I waited for a full hour in the cold wind .  
 Person2:So how long did you stay ?  
 Person1:        I left after the opening dance . I couldn't wait to get out of there . 

informal