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:       The city has got a traffic problem .  
 Person2:That means it's developing very fast .  
 Person1:        You said it .  
 Person2:Problems are inevitable . 

informal