int red_light = 3;
int blue_light = 5;
int green_light = 6;

void setup()
{
pinMode(red_light, OUTPUT);
pinMode(red_light, OUTPUT);
pinMode(green_light, OUTPUT);
}

void loop()
{
  digitalWrite(red_light, HIGH);
  digitalWrite(blue_light, HIGH);
  digitalWrite(green_light, HIGH);
  delay(1000);
  digitalWrite(red_light, HIGH);
  digitalWrite(blue_light, LOW);
  digitalWrite(green_light, LOW);
  delay(1000);
  digitalWrite(red_light, LOW);
  digitalWrite(blue_light, HIGH);
  digitalWrite(green_light, LOW);
  delay(1000);
  digitalWrite(red_light, LOW);
  digitalWrite(blue_light, LOW);
  digitalWrite(green_light, HIGH);
  delay(1000);
  digitalWrite(red_light, LOW);
  digitalWrite(blue_light, LOW);
  digitalWrite(green_light, LOW);
  delay(1000);
}