int DELAY_TIME = 4000;
int DIGITAL_PIN_7 = 7;
int DIGITAL_PIN_4 = 4;
int DIGITAL_PIN_9 = 9;

void setup() {
  // put your setup code here, to run once:
pinMode(DIGITAL_PIN_7, OUTPUT);
pinMode(DIGITAL_PIN_4, OUTPUT);
pinMode(DIGITAL_PIN_9, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
// GREEN LED
digitalWrite(DIGITAL_PIN_7, HIGH);
delay(DELAY_TIME);
digitalWrite(DIGITAL_PIN_7, LOW);

// YELLOW LED
digitalWrite(DIGITAL_PIN_4, HIGH);
delay(1000);
digitalWrite(DIGITAL_PIN_4, LOW);

// RED LED
digitalWrite(DIGITAL_PIN_9, HIGH);
delay(DELAY_TIME);
digitalWrite(DIGITAL_PIN_9, LOW);
}