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 delicious ! Tender and crisp !  
 Person2:This is the specialty of our restaurant , sir .  
 Person1:        Yes , it's really savory .  
 Person2:Thank you for appreciating it . 

informal