void setup() {
   pinMode(13, OUTPUT);
   pinMode(12, OUTPUT);
   pinMode(11, OUTPUT);

}

void loop() {
 digitalWrite (13, HIGH);
 delay(2000);
 digitalWrite (13, LOW);
 delay(200);
 digitalWrite (12, HIGH);
 delay(2000);
 digitalWrite (12, LOW);
 delay(200);
 digitalWrite (11, HIGH);
 delay(2000);
 digitalWrite (11, LOW);
 delay(200);
}