int red = 3;
int buzzer = 6;
void setup() {
  pinMode(red, OUTPUT);  
  pinMode(buzzer, INPUT);
}

void loop() {
  digitalWrite(red, HIGH);
  digitalWrite(buzzer, HIGH);
  tone(buzzer,100);
  delay(1000);

  digitalWrite(red, LOW);
  digitalWrite(buzzer, LOW);
  noTone(buzzer);
  delay(1000);
}