int red = 12;
int yellow = 11;
int green = 10;

int button = 13;
int buttonState = 0;
int state = 0;

void setup()

{
    pinMode(red, OUTPUT);   
   pinMode(yellow, OUTPUT);

pinMode(green, OUTPUT);

pinMode(button, INPUT_PULLUP);


}
void LightsOn(int greenStatus, int redStatus, int yellowStatus )

{
  digitalWrite(red, redStatus);
  digitalWrite(yellow, yellowStatus);
  digitalWrite(green, greenStatus);


}

void loop()
{
   buttonState = digitalRead(button);

   if (buttonState==LOW)
   {
     if (state == 0)
     {  
LightsOn(HIGH, LOW, LOW);
       state = 1;

   }
  else if (state == 1)
  {
  LightsOn(HIGH, HIGH, LOW);
    state = 2;
  } 
   
   else if (state == 2)
   {
LightsOn(LOW, LOW, HIGH);
   state = 3;
   }

   else if (state ==3)
   {
  LightsOn(LOW, HIGH, LOW);
    state = 0;

   }
  delay(1000);
   }


}