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:       What's wrong , Bob ?  
 Person2:I was wondering if you could company me to the Ball ?  
 Person1:        Of course , I will .  
 Person2:That's great . I'll pick you up at eight . 

informal