class CouponRateCalculator {
  static int getRate(double discount) {
    if (discount < 100) {
      String discounted = discount.toStringAsFixed(1);
      String first = discounted.substring(0, discounted.indexOf("."));
      String last = discounted.substring(discounted.indexOf(".") + 1);

      int firstNumber = int.parse(first);
      int lastNumber = int.parse(last);
      if (discount < 0.51) {
        return 0;
      } else if (discount < 2) {
        return 1;
      } else if (firstNumber < lastNumber) {
        return lastNumber;
      } else if (firstNumber > lastNumber) {
        return firstNumber;
      } else {
        return firstNumber;
      }
    } else if (discount < 1000) {
      double result = discount % 100;
      if (result == 0) {
        return 100;
      } else {
        return result.ceil();
      }
    } else {
      return 100;
    }
  }
}