#include<iostream>
//#include<iomanip>
//#include<cmath>
using namespace std;
int s=0;
class Sample
{
public:
    int m,n;
    void disp()
    {
        cout<<"m="<<m<<endl;
        cout<<"n="<<n<<endl;
    }
};
void main()
{
    int Sample::*p=&Sample::m;
    Sample a;
    a.*p=10;
    p=&Sample::n;
    a.*p=20;
    a.disp();
}