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 wish to express our desire to trade with you in leather shoes .  
 Person2:We are interested in this field .  
 Person1:        Please inform us of your decision as soon as possible . 

informal