public class CityPop implements Comparable<CityPop> {
    // store a city name and its population
    // provide a comparator with other CityPop objects

    private String name;      // beware: it may contain spaces!
    private Integer pop;      // beware: the number you read may contain commas
    
    public CityPop(String n, int p) {
	// You need to instantiate the instance variables
    }

    public String getName() {
        return name;
    }

    public Integer getPop() {
        return pop;
    }

    public int compareTo(CityPop other) {
        // This comparator leads to the wrong order
        // it will go least to largest population
        // you need the opposite
        return getPop().compareTo(other.getPop());
    }
}