#define ledRed 2
#define ledYellow 4
#define ledGreen 7

void setup() {
  pinMode(ledRed, OUTPUT);
  pinMode(ledYellow, OUTPUT);
  pinMode(ledGreen, OUTPUT);
}

void loop() {
  digitalWrite(ledRed, HIGH);
  digitalWrite(ledYellow, LOW);
  digitalWrite(ledGreen, LOW);
  delay(10000);

  digitalWrite(ledRed, LOW);
  digitalWrite(ledYellow, HIGH);
  digitalWrite(ledGreen, LOW);
  delay(3000);

  digitalWrite(ledRed, LOW);
  digitalWrite(ledYellow, LOW);
  digitalWrite(ledGreen, HIGH);
  delay(15000);

}