<reponame>xta0/data-structures-and-algorithms
#include <iostream>
using namespace std;
class MyInt {
    int nVal;
    public:
        MyInt(int n) { nVal = n; }
        int ReturnVal() { return nVal; }
// 在此处补充你的代码
    MyInt& operator-(int x){
        nVal = nVal-x;
        return *this;
    }
};
int main () {
    MyInt objInt(10);
    objInt-2-1-3;
    cout << objInt.ReturnVal();
    cout <<",";
    objInt-2-1;
    cout << objInt.ReturnVal();
    return 0;
}