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:       Can I help you , sir ?  
 Person2:Yes , I want to buy some grapes .  
 Person1:        What kind of grapes do you want ?  
 Person2:People say grapes from XinJiang are much sweeter than other kinds . Please give me a kilo of that .  
 Person1:        Ok , wait a moment please .  
 Person2:Make sure they are fresh .  
 Person1:        Trust me . 

formal