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:       Good evening , sir . What can I do for you ? 
 Person2:We are going to have a party tonight , would you please look after our baby tonight ? 
 Person1:        Well , we have baby-sitting service . We will take good care of your baby . 
 Person2:That's good . 
 Person1:        Please fill out the table . 

informal