// Your traffic light should have 3 LEDS: A red, yellow and green LED 
// The red LED should last 10 seconds, then switch to green. Green should 
// last 15 seconds, then switch to yellow. Yellow should last for 2 
// second, then switch to red. This should repeat forever.
// You should also have a button added to the arduino. If the button is 
// pressed while the light is red, it will reduce the time to 5 seconds 
// until the light turns green. If the button is pressed with less than 
// 5 seconds left on the red light, it will not change the remaining 
// time until it turns green. The button will also make the next green 
// light last 5 seconds longer if it is pressed while the light is red.
int valuered = 10000;
int valuey = 2000;
int valueg = 15000;
int timer;
int previoustime = 0;
int counter = 0;
int up = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(3, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(11, INPUT);
}

void loop() {
  timer = millis() - previoustime;
  counter = digitalRead(11);

  if (counter == HIGH){
    if (timer < 5000) {
      valuered = 5000;
      valueg = 20000;
    }
    else if (timer < 10000) {
      valueg = 20000;
    }
  }

 if (up == 0){
    if (timer < valuered){
      digitalWrite(9, HIGH);
    }
    else if (timer > valuered) {
      digitalWrite(9, LOW);
      up++;
    }
 }
 else if (up == 1){
    if (timer < (valueg + valuered)){
      digitalWrite(3, HIGH);
    }
    else if (timer > (valueg + valuered)){
      digitalWrite(3, LOW);
      up++;
    }
 }
 else if (up == 2){
    if (timer < (valueg + valuered + valuey)){
      digitalWrite(7, HIGH);
    }
    else if (timer > (valueg + valuered + valuey)){
      digitalWrite(7, LOW);
      up = 0;
      valuered = 10000;
      valueg = 15000;
      previoustime = millis();
    }
 }
 

}