final class Car{
    private final String reg;
    private final String make;
    private final int mileage;
    private final double value;
    Car(String r, String m, int mi, int v){
        reg = r; make = m;
        mileage = mi; value = v;
    }
    public String reg(){return reg;}
    public String make(){return make;}
    public String mileage(){return mileage;}
    public String value(){return value;}
}

//returns a copy of the current car
public Car copy(){
    Car copy = new Car(this.reg,this.make,this.mileage,this.value);
    return copy;
}

public boolean compareTo(Car car){
    if(this.reg == car.reg()){
        return true;
    }
    else return false;
}