int Red=4;
int Yellow=5;
int Green=6;

void setup() {
pinMode(Red, OUTPUT);
pinMode(Yellow, OUTPUT);
pinMode(Green, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(Red, HIGH);
delay(200);
digitalWrite(Yellow, HIGH);
delay(200);
digitalWrite(Green, HIGH);
delay(200);
digitalWrite(Red, LOW);
delay(200);
digitalWrite(Yellow, LOW);
delay(200);
digitalWrite(Green, LOW);
delay(200);

}