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:       Hey ! That food was terrific . I can't eat another bite . Are you sure you don't want another dish ? 
 Person2:No , I'm full . My stomach isn't growling at me any more . 
 Person1:        I know what you mean . I'm so full that I can burst . Shall we go then ? 
 Person2:I'm all set . Thank you for the dinner , Jack . 
 Person1:        You are welcome . 

informal