int buttonState;
void setup() {
  // put your setup code here, to run once:
  Serial1.begin(115200);
  Serial1.println("Hello, Raspberry Pi Pico!");

  pinMode(3, OUTPUT);
  pinMode(4, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  buttonState = digitalRead(4);
  if(buttonState == HIGH){
    digitalWrite(3, HIGH);
  }
  else{
    digitalWrite(3, LOW);
  }
}