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 . I don't think we have met before . My name is Mary Jenson .  
 Person2:Oh , hello . I'm Bias Chettri .  
 Person1:        Good to meet you , Mr Chettri .  
 Person2:Pleased to meet you too , Ms Jenson . 

informal