#define RED 14
#define YELLOW 8
#define GREEN 3

void setup() {
  pinMode(RED, OUTPUT);
  pinMode(YELLOW, OUTPUT);
  pinMode(GREEN, OUTPUT);
}

void loop() {
   digitalWrite(YELLOW, LOW);
  digitalWrite(GREEN, LOW);
  digitalWrite(RED, HIGH);
  delay(20000);
  digitalWrite(RED, LOW);
  digitalWrite(GREEN, HIGH);
  digitalWrite(YELLOW, LOW);
  delay(10000);

 
   digitalWrite(GREEN, LOW);
  digitalWrite(RED, LOW);
  digitalWrite(YELLOW, HIGH);
  delay(2000);
 
}