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:       Oh , Ralph , I heard it is very dangerous traveling in space . Disasters have happened before . If the spaceship were out of order . . .  
 Person2:You should be optimistic about this . Things have taken a good turn . You should remember that less than two centuries ago the dangers of train travel seemed similarly terrible .  
 Person1:        But is it possible that travelers could be hit by meteors ?  
 Person2:It's once in blue moon .  
 Person1:        What do you think is the real danger man faced in space ?  
 Person2:The main one is radiation . There are two sorts of radiation man must fear in space . The first is radiation from the sun , and this is particularly dangerous when the sun is very active and explosions are occurring on its surface . The second , less harmful , comes from the so-called Van Allen Belts . 

formal