int led1=9;
int led2=8;
int led3=7;
void setup() {
  // put your setup code here, to run once:
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  // Stage 1//
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  delay(1000);

// Stage 2//
  digitalWrite(led1, HIGH);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  delay(1000);

  // Stage 3//
   digitalWrite(led1, LOW);
  digitalWrite(led2, HIGH);
  digitalWrite(led3, LOW);
  delay(1000);

  // Stage 4//
   digitalWrite(led1, LOW);
  digitalWrite(led2, HIGH);
  digitalWrite(led3, HIGH);
  delay(1000);

  // Stage 5//
   digitalWrite(led1, HIGH);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  delay(1000);

  // Stage 6//
   digitalWrite(led1, HIGH);
  digitalWrite(led2, LOW);
  digitalWrite(led3, HIGH);
  delay(1000);

  // Stage 7//
   digitalWrite(led1, HIGH);
  digitalWrite(led2, HIGH);
  digitalWrite(led3, LOW);
  delay(1000);

  // Stage 8//
   digitalWrite(led1, HIGH);
  digitalWrite(led2, HIGH);
  digitalWrite(led3, HIGH);
  delay(1000);


}