int LED1=10,LED2=9,LED3=8;
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:
  digitalWrite(LED1, HIGH);
  delay(100);
  digitalWrite(LED1,LOW);
  delay(100);
  digitalWrite(LED2, HIGH);
  delay(100);
  digitalWrite(LED2, LOW);
  delay(100);
  digitalWrite(LED3, HIGH);
  delay(100);
  digitalWrite(LED3, LOW);
  delay(100);
}