import java.util.ArrayList;

public class MainClass {
	/**
	 * Prints the cheapest weekly rate available among a fleet 
	 * of vehicles, or prints that no vehicle can be rented.
	 * @param v the list of vehicles
	 */
	public void printCheapestWeeklyRate(ArrayList v) {
		double cheapestSoFar = 0; // the value is irrelevant
		boolean foundRentable = false;
		for (Object obj: v) {
			if (obj instanceof Rentable) {
				Rentable r = (Rentable) obj;
				if (!foundRentable) { // first one
					cheapestSoFar = r.getWeeklyRate();
					foundRentable = true;
				}
				else if (r.getWeeklyRate() < cheapestSoFar) {
					cheapestSoFar = r.getWeeklyRate();
				}
			}
		}
		
		if (foundRentable) {
			System.out.println("Cheapest rate = " + cheapestSoFar);
		}
		else {
			System.out.println("No vehicle can be rented.");
		}
	}

}

abstract class Vehicle {
	public boolean startEngine() {
		return false;
	}

	public abstract int getMaxSpeed();

	public abstract double getVehicleValue();
}

interface Rentable {
	public double getWeeklyRate();
}

interface UsesPremiumGas {
	public void fillTankWithPremiumGas(double gallons);
}

class Car extends Vehicle implements Rentable {

	public int getMaxSpeed() {
		return 0;
	}

	public double getVehicleValue() {
		return 0;
	}

	public double getWeeklyRate() {
		return 0;
	}
}

class FancyCar extends Car implements UsesPremiumGas {
	public void fillTankWithPremiumGas(double gallons) {
	}
}

class Bus extends Vehicle {
	public int getMaxSpeed() {
		return 0;
	}

	public double getVehicleValue() {
		return 0;
	}
}