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:       They are a nice middle-aged couple , just like us .  
 Person2:If they are just like us , they are not middle-aged .  
 Person1:        Of course they are .  
 Person2:Middle-aged means in the middle , Ethel , middle of life . People don't live to a hundred and fifty .  
 Person1:        Oh , we are the part on the edge of middle . That's all .  
 Person2:Oh , you know , we are not middle-aged . You're old , and I'm aging .  
 Person1:        Oh , fool ! You're nearly seventy and I'm in the low sixties . Would you like to spend the rest of the afternoon squabbling about this ?  
 Person2:I can if you like . 

informal