menghitung luas 2 kerucut c++ "program modify 3(b)"

#include <iostream>
using namespace std;
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
class kerucut{
int la;
int ls;
public:
void luas_kerucut(int,int);
luas(){return(la+ls);
}
};
void kerucut::luas_kerucut(int x,int y){
la=x;
ls=y;
}
int main(int argc, char** argv) {
kerucut a,b;
int x,y;
cout<<"Luas alas: ";cin>>x;
cout<<"Luas selimut:";cin>>y;
a.luas_kerucut(x,y);
b.luas_kerucut(11,5);
cout<<"Luas Kerucut A: "<<a.luas()<<endl;
cout<<"Luas Kerucut B: "<<b.luas();
return 0;
}