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:       Are you free this Saturday evening ?  
 Person2:Oh , it seems there is nothing that evening .  
 Person1:        Would you like to go to the concert with me ?  
 Person2:I'd like to , where ?  
 Person1:        At our club .  
 Person2:When ?  
 Person1:        At 7:30 p . m .  
 Person2:I'll go in time , thank you .  
 Person1:        I'm so pleased that you can go . 

informal