void setup() {
 

  for (int i = 2; i <= 6; i++)
  {
    pinMode(i, OUTPUT);
  }


}

void loop() {
  

  for (int i = 2; i <= 6; i++)
  {

    int linkerPin = ((i + 2)  % 5) + 2;

    digitalWrite(i, HIGH);
    digitalWrite(linkerPin, LOW);
    delay(500);

  }

}