//use for loop for Traffic light

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

void loop() {
  digitalWrite(2, HIGH);
  delay(1000);
  digitalWrite(2, LOW);
  delay(1000);

  digitalWrite(4, HIGH);
  delay(1000);
  digitalWrite(4, LOW);
  delay(1000);

  digitalWrite(6, HIGH);
  delay(1000);
  digitalWrite(6, LOW);
  delay(1000);
}