void setup() {
   pinMode(10, OUTPUT); 
   pinMode(9, OUTPUT);
   pinMode(8, OUTPUT);
  
  digitalWrite(10, 1);
  delay(500);
  digitalWrite(10, 0);
  delay(500);
 
  digitalWrite(9, 1);
  delay(500);
  digitalWrite(9, 0);
  delay(500);
 
  digitalWrite(8, 1);
  delay(500);
  digitalWrite(8, 0);
  delay(500);

}

void loop() {
  // put your main code here, to run repeatedly:

}