void setup() 
{
   pinMode (2,OUTPUT);
   pinMode (3,OUTPUT);
   pinMode (5,OUTPUT);
}


void loop() 
{
  int n,i;
  for(n=1;n<=25;n++)
  {
   digitalWrite(2,1);
   digitalWrite(3,1);
   digitalWrite(5,1);
   delay(1);
  
   for(i=1;i<=19;i++)
   {
   digitalWrite(2,0);
   if(i>=8)
   digitalWrite(3,0);
   if(i>=16)
   digitalWrite(5,0);
   delay(1);
   }
  }
    delay(500);
}