void setup() {
  // put your setup code here, to run once:


  for(int i=2;i<=9;i++)
    pinMode(i, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:



  for (int i=2;i<=9;i++)
  {
      digitalWrite(i, HIGH);
      delay(200);
      digitalWrite(i, LOW);

  }
  for (int i=8;i>=3;i--)
  {
      digitalWrite(i, HIGH);
      delay(200);
      digitalWrite(i, LOW);

  }

  

}