void setup() {
  // put your setup code here, to run once:
pinMode(2,OUTPUT );
pinMode(7,OUTPUT );
pinMode(8,OUTPUT );
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(2,HIGH );
delay(50);
digitalWrite(2,LOW );
delay (500);
digitalWrite(7,HIGH );
delay (50);
digitalWrite(7,LOW );
delay(500);
digitalWrite (8,HIGH );
delay(50);
digitalWrite(8,LOW );
delay(500);
}