#include <iostream>
#include <string>
using namespace std;
class damon{
int a;
public:
damon(){
a=0;
}
damon(int b){
a=b;
}
void operator-=(int wolf){
a=a-wolf;
}
void depict(){
cout<<a<<endl;
}
};
int main (){
damon vamp(80);
vamp-=10;
vamp.depict();
return 0;
}
