void main() {
  // 1. Set Water Usage Limit
  int waterLimitLiters = 250;
  int currentUsage = 0;
  
  // 5. Track Water Usage for 24 hours
  print("--- Tracking Water Usage ---");
  for (int hour = 1; hour <= 24; hour++) {
    currentUsage += 10; // Assuming 10 liters used per hour
    
    // 2. Monitor Usage
    if (currentUsage > waterLimitLiters) {
       print("Hour $hour: Usage exceeded the daily limit of $waterLimitLiters liters!");
       break; // Stop tracking if limit exceeded early
    }
    
    // 3. String Concatenation & 4. Upper/Lowercase Alert
    if (currentUsage == 100) {
      String alertMsg = "Alert: " + "Water usage has reached 100 liters.";
      print(alertMsg.toUpperCase());
    }
  }
  
  print("\nTotal water used today: $currentUsage liters");
  
  // 6. Discount for Conserving Water
  if (currentUsage < 200) {
    print("Great job! You used less than 200 liters. A 5% discount is applied to your bill.");
  } else {
    print("You used 200 liters or more. No discount applied today.");
  }
}