void setup() {
  // put your setup code here, to run once:
  pinMode(12,OUTPUT);
  pinMode(13,OUTPUT);
  pinMode(14,OUTPUT);
}

void loop()
{
 for(int i=0;i<=7;i++)
 {
  if(i==1 || i==3 || i==5 || i==7)
  {
   digitalWrite(12,HIGH);
  }
         else
  {
   digitalWrite(12,LOW);
  }
  if(i==2 || i==3 || i==6 || i==7)
  {
   digitalWrite(13,HIGH);
  }
  else
  {
   digitalWrite(13,LOW);
  }
  if(i>3)
  {
   digitalWrite(14,HIGH);
  }
  else
  {
   digitalWrite(14,LOW);
  }

  delay(500);
 }
}