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:       Welcome to our shop . It seems you are interested in this dress . 
 Person2:Yes . But I am afraid it is too thick to wear in summer . 
 Person1:        That's no problem . It is made of linen , so you won't feel hot in it . I can assure you it is of superior quality . What is more , it is very popular with young women . 
 Person2:How much is it ? 
 Person1:        88 Yuan . 
 Person2:OK , that is reasonable . I will take it . 

formal