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:       We're forming a study group to prepare for the finals . Do you want to join us ?  
 Person2:But the semester just started ? Why the rush ?  
 Person1:        After you try it once this way , I don't think you'll ever put off studying till the end again .  
 Person2:How often do you meet ?  
 Person1:        We plan to get together once a week .  
 Person2:What days , do you know ?  
 Person1:        We were talking about Wednesday evenings at the library , from seven to eight .  
 Person2:Okay , count me in . 

informal