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:       Let ’ s go to the seashore on Saturday .  
 Person2:Yes ! Let ’ s go sailing and water skiing . That ’ s so exciting .  
 Person1:        It ’ s expensive , too . Let ’ s just sit in the sun and go swimming instead .  
 Person2:Yes . Let ’ s sleep on the sand . That ’ s most exciting ! 

informal