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:       Did you get a nice tree ? 
 Person2:Sure did . It's a beauty . Where do you want it ? 
 Person1:        Let's put it over there . 
 Person2:Let's go to work . We want to have the tree ready to light up by evening . 
 Person1:        Let's string the lights first.Then we won't have to mess up the decorations . 
 Person2:Hand me some globes and paper flowers , I'll put them on these top branches . 
 Person1:        There , ... we're about done . 
 Person2:Let's switch the lights on . 
 Person1:        OK . Here goes . 
 Person2:Well , I guess we're all set for another merry Christmas . 

informal