import java.util.*;
import java.lang.*;
import java.io.*;

public class Main {
    public static void swap(Object a, Object b) {
        try {
            java.lang.reflect.Field value = a.getClass().getDeclaredField("value");
            value.setAccessible(true);
            Object tmp = value.get(a);
            value.set(a, value.get(b));
            value.set(b, tmp);
        } catch (Exception e) {}
    }
    
    public static void main(String[] args) {
        String first = "first";
        String second = "second";
        System.out.println(first+" "+second);
        swap(first, second);
        System.out.println(first+" "+second);
        
        System.out.println();
        
        Integer x = 1;
        Integer y = 2;
        System.out.println(x+" "+y);
        swap(x, y);
        System.out.println(x+" "+y);
    }
}