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

}

void loop() {
  // put your main code here, to run repeatedly:
   digitalWrite(5, LOW);
   digitalWrite(4, HIGH);
   delay(200);
   digitalWrite(5, HIGH);
   digitalWrite(4, LOW);
   delay(200);
}