int buttonPin = 2;  // Button connected to digital pin 2
 int redLedPin = 3;  // Red LED connected to digital pin 3
 int greenLedPin = 4; // Green LED connected to digital pin 4

void setup() {
  pinMode(buttonPin, INPUT_PULLUP); // Set button pin as input with internal pull-up resistor
  pinMode(redLedPin, OUTPUT);      // Set red LED pin as output
  pinMode(greenLedPin, OUTPUT);    // Set green LED pin as output
}

void loop() {
  // Read the button state (LOW when pressed, HIGH when not pressed)
  int buttonState = digitalRead(buttonPin);

  if (buttonState == LOW) {
    digitalWrite(redLedPin, LOW);  // Turn off the red LED
    digitalWrite(greenLedPin, HIGH); // Turn on the green LED
  } else {
    digitalWrite(redLedPin, HIGH); // Turn on the red LED
    digitalWrite(greenLedPin, LOW); // Turn off the green LED
  }
}