int button_state = 0;
void setup() {
  // put your setup code here, to run once:
  pinMode(2, OUTPUT);
  pinMode(0, OUTPUT);
  pinMode(16, INPUT_PULLUP);
}

void loop() {
  int button_state = digitalRead(16);
  if (button_state == LOW)
  {
    tone(2,1,1); 
  } 
  else
  {
  tone(0,1,1);
  }
}