class Pair<T> {
    private T first;
    private T second;

    public Pair(T x1, T x2) {
        first = x1;
        second = x2;
    }

    @Override
    public String toString() {
        return "(1)" + first + " (2)" + second;
    }

    public T getFirst() {
        return first;
    }

    public T getSecond() {
        return second;
    }
}

class UnorderedPair<T> extends Pair<T> {
    public UnorderedPair(T firstItem, T secondItem) {
        super(firstItem, secondItem);
    }

    public boolean equals(Object otherObject) {
        if (otherObject == null)
            return false;
        else if (getClass() != otherObject.getClass())
            return false;
        else {
            UnorderedPair<T> otherPair = (UnorderedPair<T>) otherObject;
            return 
                ( getFirst().equals(otherPair.getFirst()) && 
                  getSecond().equals(otherPair.getSecond()) ) || 
                ( getFirst().equals(otherPair.getSecond()) && 
                  getSecond().equals(otherPair.getFirst()));
        }
    }
}

public class Main {
    public static void main(String[] args) {
        UnorderedPair<String> x1 = new UnorderedPair<>("ABC", "DEF");
        UnorderedPair<String> x2 = new UnorderedPair<>("DEF", "ABC");
        UnorderedPair<String> x3 = new UnorderedPair<>("DEF", "AAA");
        System.out.println(x1.equals(x2));// true
        System.out.println(x1.equals(x3));// false
    }
}