#define ledRED 18
#define ledYELLOW 5
#define ledGREEN 4
#define ledBLUE 2


void setup() {

 pinMode(ledRED , OUTPUT);
 pinMode(ledYELLOW, OUTPUT);
 pinMode(ledGREEN, OUTPUT);
 pinMode(ledBLUE, OUTPUT);
  
}

void loop() {

  digitalWrite(ledBLUE, HIGH);
  delay(300);
  digitalWrite(ledBLUE, LOW);
  delay(300);

  digitalWrite(ledGREEN, HIGH);
  delay(300);
  digitalWrite(ledGREEN, LOW);
  delay(300);

  digitalWrite(ledYELLOW, HIGH);
  delay(300);
  digitalWrite(ledYELLOW, LOW);
  delay(300); 
  
  digitalWrite(ledRED, HIGH);
  delay(300);
  digitalWrite(ledRED, LOW);
  delay(300);

}