void setup() {
  // put your setup code here, to run once:
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(A0, INPUT);
 
}

void loop() {
  // put your main code here, to run repeatedly:
  int value;
  value = analogRead(A0);
  // Value is changeable
  if (value > 500){
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
    }
    else{
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, HIGH);
    }
    delay(0);//no delay time
}