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:       Hey , John ! What do you think are the main causes of war today ? 
 Person2:It's hard to say ! But it seems that a lot of wars nowadays are civil wars . People from different ethnic groups in the same country sometimes fight for power in that country . 
 Person1:        Yeah , several of those civil wars have been going on for years and years . It seems they will never end . 
 Person2:How do you think they could be ended ? 
 Person1:        I don't think that there is any easy way . 
 Person2:I think one better way to stop it is to cut off their financial support . 
 Person1:        Yeah , you are right ! 

formal