int red_led=2;
int yallow_led=8;
int green_led=13;


void setup() {
  pinMode(red_led, OUTPUT);
  pinMode(yallow_led, OUTPUT);
  pinMode(green_led, OUTPUT);

}

void loop() {
digitalWrite(red_led,HIGH);
digitalWrite(yallow_led,LOW);
digitalWrite(green_led,LOW);
delay(2000);
digitalWrite(red_led,LOW);
digitalWrite(yallow_led,HIGH);
digitalWrite(green_led,LOW);
delay(2000);
digitalWrite(red_led,LOW);
digitalWrite(yallow_led,LOW);
digitalWrite(green_led,HIGH);
delay(2000);
digitalWrite(red_led,LOW);
digitalWrite(yallow_led,HIGH);
digitalWrite(green_led,LOW);
delay(1000);



}