///程序填空，使其输出9 22 5
#include <iostream>
using namespace std;
class Sample {
public:
    int v;
    Sample()
    {
        v=0;
    }
    Sample(int i)
    { 
        v=i;
    } 
    Sample(Sample const &a)
    {
        v=a.v+2;
    }   
    
};
void PrintAndDouble(Sample o)
{
    cout << o.v;
    cout << endl;
}
int main()
{
    Sample a(5);
    Sample b = a;
    PrintAndDouble(b);
    Sample c = 20;
    PrintAndDouble(c);
    Sample d;
    d = a;
    cout << d.v;
    return 0;
}