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:       May I bring you a salad ?  
 Person2:Oh , yes.What do you recommend today ?  
 Person1:        Rose-petal salad .  
 Person2:OK , I'll have it for change . 

formal