int lvl = 0;

void setup() {
  pinMode(A5, INPUT);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  lvl = analogRead(A5);
  Serial.println(lvl);
  if(lvl == 0){
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
  }
  if(lvl >= 1 && lvl <= 250){
    digitalWrite(2, HIGH);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
  }
  else if(lvl >= 251 && lvl <= 750){
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, LOW);
  }
  else if(lvl >= 751 && lvl <= 1023){
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, HIGH);
  }
}