void setup() {
  // put your setup code here, to run once:
pinMode(15,OUTPUT);
pinMode(16, OUTPUT);
pinMode(17, OUTPUT);


}


void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(15, HIGH);
delay(100);
digitalWrite(15,LOW);
delay(100);
digitalWrite(16, HIGH);
delay(100);
digitalWrite(16,LOW);
delay(100);
digitalWrite(17, HIGH);
delay(100);
digitalWrite(17,LOW);
delay(100);
}