void setup() {
  // put your setup code here, to run once:
  pinMode(13, OUTPUT);

  // turn light on for 5 seconds then off for 5 seconds 
  digitalWrite(13, HIGH);
  delay(5000);
  digitalWrite(13, LOW);
  delay(5000);

  // turn light on for 4 seconds then off for 4 seconds
  digitalWrite(13, HIGH);
  delay(4000);
  digitalWrite(13, LOW);
  delay(4000);

  // turn light on for 3 seconds then off for 3 seconds
  digitalWrite(13, HIGH);
  delay(3000);
  digitalWrite(13, LOW);
  delay(3000);

  // turn light on for 2 seconds then off for 2 seconds
  digitalWrite(13, HIGH);
  delay(2000);
  digitalWrite(13, LOW);
  delay(2000);

  // turn light on for 1 seconds then off for 1 seconds
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);

  // turn light on for 1.5 seconds
  digitalWrite(13, HIGH);
  delay(1500);
}

void loop() {
  // turn the light on for 0.5 seconds
  digitalWrite(13, HIGH);
  delay(500);

  // turn the light off for 0.5 seconds
  digitalWrite(13, LOW);
  delay(500);


}