有以下程序:
#include<iostream>
using namespace std;
class Base
public:
Base()
x=0;
int x;
;
class Derivedl:virtual public Base
public:
Derivedl()
x=10;
;
class Derived2:virtual public Base
public:
Derived2()
x=20;
;
class Derived:public Derivedl,protected Derived2
;
int main()
Derived obj;
cout<<obj.x<<endl;
return 0;
该程序运行后的输出结果是______。