int last = 0; // Global variable declaration
byte state = 0; // Global variable declaration

void setup() {
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  if (millis() - last >= 1000) {
    last = millis();

    switch (state) {
      case 0:
        Serial.println("RED");
        digitalWrite(13, HIGH);
        digitalWrite(12, LOW);
        digitalWrite(11, LOW);
        break;
      case 1:
        Serial.println("RED+ORANGE");
        digitalWrite(13, HIGH);
        digitalWrite(12, HIGH);
        digitalWrite(11, LOW);
        break;
      case 2:
        Serial.println("GREEN");
        digitalWrite(13, LOW);
        digitalWrite(12, LOW);
        digitalWrite(11, HIGH);
        break;
      case 3:
        Serial.println("ORANGE");
        digitalWrite(13, LOW);
        digitalWrite(12, HIGH);
        digitalWrite(11, LOW);
        break;
    }

    state = (state + 1) % 4; // Simplified state change using modulo operator
  }
}