const int buttonPin = 27;  // the number of the pushbutton pin
const int ledPin1 = 26;    // the number of the first LED pin
const int ledPin2 = 0;    // the number of the second LED pin
const int ledPin3 = 1;    // the number of the third LED pin

int buttonState = 0;  // variable for reading the pushbutton status
int lastButtonState = 0; // variable to store the previous state of the button
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50;    // the debounce time; increase if the output flickers

void setup() {
  pinMode(buttonPin, INPUT);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  // Initialize serial communication:
  Serial.begin(9600);
}

void loop() {
  // read the state of the pushbutton value:
  int reading = digitalRead(buttonPin);

  // check if the button state has changed
  if (reading != lastButtonState) {
    // reset the debouncing timer
    lastDebounceTime = millis();
  }

  // if a certain amount of time has passed since the last change
  if ((millis() - lastDebounceTime) > debounceDelay) {
    // if the button state has changed
    if (reading != buttonState) {
      buttonState = reading;

      // check if the button is pressed
      if (buttonState == HIGH) {
        // increment LED count
        static int ledCount = 0;
        ledCount++;

        // turn off all LEDs
        digitalWrite(ledPin1, LOW);
        digitalWrite(ledPin2, LOW);
        digitalWrite(ledPin3, LOW);

        // light LEDs according to button presses
        if (ledCount == 1) {
          digitalWrite(ledPin1, HIGH);
          Serial.println("First LED on");
        } else if (ledCount == 2) {
          digitalWrite(ledPin2, HIGH);
          Serial.println("Second LED on");
        } else if (ledCount == 3) {
          digitalWrite(ledPin3, HIGH);
          Serial.println("Third LED on");
        } else if (ledCount >= 4) {
          digitalWrite(ledPin3, LOW);
          Serial.println("LEDs off");
          // reset LED count after lighting the third LED
          ledCount = 0;
        }
      }
    }
  }

  // save the current button state for comparison in the next loop iteration
  lastButtonState = reading;
}