 const int LOOP_LENGTH = 50;
 
 int distance;
+int led = 13;
 boolean is_hand = false;
 unsigned long time;
 unsigned long loop_delay;

  // initialize serial communication at 9600 bits per second:
  Serial.begin(115200);
  Dist.begin(A0);
}

// the loop routine runs over and over again forever:

     if (is_hand) {
      is_hand = false;
      Serial.println("OFF");
      digitalWrite(led, LOW);  
    }
  }    
  int loop_delay = LOOP_LENGTH - (time - millis());
