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'.

Person1: Excuse me , miss.Should I check in here for taking MS121 to Florence ?
Person2:Yes , show me your ticket and passport please .
Person1: Here you are . Can I have a seat in the back of the plane ?
Person2:No problem . Wish you a nice trip .
formal