// Vehicle.java

class Vehicle {

    private int topSpeed;

    Vehicle() {}

    public void setTopSpeed(int topSpd) {
        topSpeed = topSpd;
    }
 
    public int getTopSpeed() {
        return topSpeed;
    }

    public int changeTopSpeed1(int topSpeed) {
        topSpeed = topSpeed;
        return this.topSpeed;
    }

    public int changeTopSpeed2(int topSpeed) {
        this.topSpeed = topSpeed;
        return this.topSpeed;
    }

    public void changeTopSpeed3(int topSpeed) {
        topSpeed = topSpeed;
    }

    public void maximiseTopSpeed(int topSpeed) {
        topSpeed = 300;
    }

}