import java.util.*;

public class Parameters3 {

    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));
        for (int i=0; i<X.length; i++) {
            int temp = X[i];
            X[i] = Y[i];
            Y[i] = temp;
        }
        System.out.println ("  AFTER:  X=" + Arrays.toString(X) + " Y=" + Arrays.toString(Y));
    }

}