***** 원본글 *****
package step01;

class DBox<L,R> {
private L left;
private R right;

public void set(L o, R r) {
left = o;
right = r;

}
@Override
public String toString() {
return right + "&" + left;
}
}
class DDBox<U,D> {
private U u;
private D d;

public void set(U u,D d) {
this.u = u;
this.d = d;
}
@Override
public String toString() {
return u + "&" + d;
}
}


public class Exam06 {

public static void main(String[] args) {
DBox<String,Integer> box1 = new DBox<String,Integer>();
box1.set("Apple", 25);

DBox<String,Integer> box2 = new DBox<String,Integer>();
box2.set("Orange", 33);
DDBox<DBox<String, Integer>,DBox<String, Integer>> ddbox = new DDBox<>();
ddbox.set(box1,box2);
System.out.println(ddbox);

}

}