class Microwave {

    Food contents;
    double seconds;

    Microwave() {
        this.contents = null;
        this.seconds = 0.0;
    }

    void enterTime(double seconds) {
        this.seconds = seconds;
    }

    double getTime() {
        return this.seconds;
    }

    void pressCookButton() throws Exception {
        if (this.seconds == 0) {
            throw new Exception("No time entered!");
        }
        if (this.contents == null) {
            throw new Exception("Nothing in microwave!");
        }
        this.contents.heat(this.seconds);
        this.seconds = 0.0;
    }

    void insert(Food f) throws Exception {
        if (this.contents != null) {
            throw new Exception();
        }
        this.contents = f;
    }

    Food remove() throws Exception {
        if (this.contents == null) {
            throw new Exception();
        }
        Food f = this.contents;
        this.contents = null;
        return f;
    }
}