const int redPin = 2;
const int yellowPin = 3;
const int greenPin = 4;
const int pedestrianButtonPin = 5;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(pedestrianButtonPin, INPUT_PULLUP);
}

void loop() {
  if (digitalRead(pedestrianButtonPin) == LOW) {
    // Pedestrian button pressed
    pedestrianMode();
  } else {
    // Normal traffic light operation
    normalOperation();
  }
}

void changeColor(int pin, int duration) {
  digitalWrite(redPin, LOW);
  digitalWrite(yellowPin, LOW);
  digitalWrite(greenPin, LOW);

  digitalWrite(pin, HIGH);
  delay(duration * 1000);
}

void normalOperation() {
  changeColor(redPin, 5);
  changeColor(yellowPin, 2);
  changeColor(greenPin, 5);
}

void pedestrianMode() {
  changeColor(yellowPin, 1);
  changeColor(greenPin, 5);
  normalOperation();
}