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:       My shirt needs ironing . Could you please help me with that , Mary ? 
 Person2:No way . Do it yourself . 
 Person1:        Please , I promise this is the last time . 
 Person2:OK , I'll iron your shirt for you , but only if you make me a cup of coffee . 

informal