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:       Shakespeare was born in 1867 .  
 Person2:No , it sounds wrong . He was born in the 16th century .  
 Person1:        Are you sure ? Can you make it more exact ?  
 Person2:1564 . 

formal