单项选择题

有如下程序：
#include＜iostream＞
using namespace std;
class Base{
public:
Base(int x=0):valB(x){cout＜＜valB;}
～Base(){cout＜＜valB;}
private:
int valB;
};
class Derived:public Base{
public:
Derived(int x=0,int y=0):Base(x),valD(y){cout＜＜valD;}
～Derived(){cout＜＜valD;}
private:
int valD;
};
int main(){
Derived obj12(2,3);
return 0;
}
运行时的输出结果是______。

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