None. The darkness will cause the bulb to change by itself.
  
               
   
            
            
			
       
           
       
           
            or
           
       
      
       
            
            You're the only bright spot in my life.
  
               
   
            
            
			
       
           
       
           
            or
           
       
      
       
            
              
             
            
			  
            
            He was trying to fetch a boomerang
  
               
   
            
            
			
       
           
       
           
            or
           
       
      
       
            
            It left its tracks.
  
               
   
            
            
			
       
           
       
           
            or
           
       
      
       
            
              
             
            
			  
            
            You crack me up!
  
               
   
            
            
			
       
           
       
           
            or
           
       
      
       
            
              
             
            
			  
            
            Because he has such yuuuuge fans!  
               
   
            
            
			
       
           
       
           
            or
           
       
      
       
            
            Cause your the only one Hair. 
  
               
   
            
            
			
       
           
       
           
            or