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:       Do you like that vintage clock ? It's almost fifty years old .  
 Person2:Really ? It almost looks brand new . And the color designs are so retro .  
 Person1:        Well , in the fifties , that clock used to be inside a drive-in burger joint .  
 Person2:No way ! My parents used to hang out at those places .  
 Person1:        This is one of my favorite items .  
 Person2:How did you get it ? 

informal