import java.util.*;

public class Parameters2 {

    public static void main (String[] argv)
    {
        int[] A = {1, 2};
        int[] B = {3, 4};
        
        System.out.println ("BEFORE: A=" + Arrays.toString(A) + " B=" + Arrays.toString(B));

        swap (A, B);
        System.out.println ("AFTER:  A=" + Arrays.toString(A) + " B=" + Arrays.toString(B));
    }

    static void swap (int[] X, int[] Y)
    {
        System.out.println ("  BEFORE: X=" + Arrays.toString(X) + " Y=" + Arrays.toString(Y));
        int[] temp = X;
        X = Y;
        Y = temp;
        System.out.println ("  AFTER:  X=" + Arrays.toString(X) + " Y=" + Arrays.toString(Y));
    }

}