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:       Hi ! My name is Mike .  
 Person2:Hi ! I'm Nancy . Nice to meet you .  
 Person1:        Nice to meet you , too .  
 Person2:Where are you from ?  
 Person1:        I'm from Shanghai . And you ?  
 Person2:I'm from Chicago . 

informal