void setup() {
  // put your setup code here, to run once:
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(4, HIGH);//Turn the first LED on
digitalWrite(5, LOW);// Turn the second LED off
digitalWrite(3, HIGH);//Turn the third LED on
delay(1000);// Wait for 1 seconds

digitalWrite(4, LOW);//Turn the first  LED off
digitalWrite(5, HIGH);// Turn the second LED on
digitalWrite(3, LOW);//Turn the third LED off
delay(1000);// Wait for 1 seconds
}