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:       We have a variety of trousers . Which one do you like best ?  
 Person2:I want to buy one to match my shirt.Can you give me some advice ?  
 Person1:        What about this one ?  
 Person2:Yes , they seem to be my size and go with my shirt quite well . I will take it . 

formal