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:       Excuse me , are you Sara Wilson ?  
 Person2:Yes , I am . You must be Tom . Nice to meet you .  
 Person1:        Nice to meet you too . Let me help you with your bags .  
 Person2:Be careful , Tom . Those are pretty heavy .  
 Person1:        Wow , you're not kidding . Hold on a second . Hello , could you give us a hand , please ? 

informal